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10



10.1              F
                                  F
                                          F                                                                                                  F                             F           (Q)           F               (J)

         -                                                    F   1                           (= 4.186 J )                                                                     F                 F           1
         1° C

10.1.1
                                                                                               F                                                                   F
                      F               F                                                            F           F                                                                                                 F
              F                                           F                   F

10.2.1                    F                       F
                              F                       F                   F           F                                                 F                                                    F           F
                                              F                   F                                                        F                     F       F
                                                                     F                                 F           F
         1.                                                        (° C)
         2.                                                   (K)      F                                                           F FF              F       F                         F             (                     F
                                                                  SI)

                                                      K                           °C
                                      373.16                                      100
                                                                                                                       F            F                            K = C + 273

                                      273.16                                      0



                                                                                          F
                                                                                                                                            C=
                                                                                                                                            R=                         F
                                      = =
                                                                                                                                            F=                                     F
                                                                                                                                            K=
                                                                      –                                    F                   F             www.schoolDD.com                                                                  1
10.1.2                           F
         1.                              F    (C)                                                     F                   F
                                                           F       F                          F                       (J/K)

                                               〉 ∆T
                                 m                                             C=
                                              ∆Q




         2.                          F                 (c )                                                       F                  F      1     F
                                                         F     F                          F                                        (J/kg K)
                                               〉 ∆T
                                 m
                                              ∆Q                               c=


                F           FF                         F                   F                          m                                 ΔT      F F
                                                                               Q=                                            F           (J)
                                                                               m=                                           (kg)
                    Q = mc∆T
                                                                               c=                                       F                       (J/kg K)
                                                                               ΔT =                                                          (K        ˚C)

-                   F       (C)                                                       F                               F F                  C             F   C F
-                       F                    (c)                                                          F F

                                                                                                  F                         c (J/kg K)
                                                                                                           4186
              (-10˚C             0˚C)                                                                      2100
                                                                                                            900
                                                                                                            450
                                                                                                            390
                                                                                                            140
                                                                                                            130



                                                   –                   F          F                        www.schoolDD.com                                        2
F 1                                                                                     F                   F                                                          100                     25˚C ( c             = 390
    J/kg K)
          .                                                                           45 ˚C
          .                                                                           15 ˚C
           . F                                     F                                    F   F                                                                            F
                                                                            Q = mc∆T
                                                                              = 0.10x390x(45-25)
                                                                            Q = 780 J Ans


             .                                                          F                                                 F                                                      F
                                                                            Q = mc∆T
                                                                              = 0.10x390x(25-15)
                                                                            Q = 390 J Ans


10.1.4                                                                                                    F
                                       F                                    F                                                     F                                                          F
                                                                                                                                          F                 F                        F
                       F



                                                                                                                                                                     s




         -                                                                                                                                                                                           F
    F                                                                             F           F               F                       F                                      F F

10.1.5                                                          F
                               3
                                               F                    F                     F                                   F                                                                              F
                                   F                        F

                                                       F                                                                                                         F           F           F                          F
                 F F                       F                                                                                                      F F

             F             F                                                    F F                   F                                                 F                                        F                      F F
                                                           F F
                                                                                      –                           F                           F                 www.schoolDD.com                                                  3
F          F

                                                                      F


                                                                                                                             F



                                                                                                 F




                                                        F




                          F                    F        m                                                    F                         F F
                                                                     Q=                               F      (J)
                         Q = mL                                      m=                              (kg)
                                                                     L=                F                                                            (J/kg)

                                                                F                                                                F
                                                                           Lm (J/kg)                                                       Lv (J/kg)
                                                                      333x103                                                        2256x103
                                                                      58.6x103                                                        452x103
                                                                      5.23x103                                                       20.9x103

     F       2                             F                              F                200                          -10˚ C
           F                 F                 190                                          (                  c        = 2100 J/kg K, c =
                        3                  3
4186 J/kg K, Lm = 333x10 J/kg, Lv = 2256x10 J/kg )
                                                                                             “         F            F
                                                                                                      F F      F         F             F     F ”

                    Q1                             Q2                                 Q3                                Q4



            200 g                    200 g                                200 g                             200 g                            190 g +         10 g
   -10° C                     0° C                                  0° C                              100° C                               100° C




                                       –                    F                 F       www.schoolDD.com                                                          4
F                F            200 g -10° C                                       0° C
                                      Q1 = mc∆T
                                         = 0.2x2100x(0-(-10))
                                      Q1 = 4200 J
                          F                 F       200 g 0° C                                                     0° C
                                      Q2 = mL
                                         = 0.2x333x103
                                      Q2 = 66600 J
                          F                   F 200 g 0° C                                                    100° C
                                      Q3 = mc∆T
                                         = 0.2x4186x(100-0)
                                      Q3 = 83720 J
                          F                        F 10 g 100° C                                 10 g 100° C
                                      Q4 = mL
                                         = 0.01x2256x103
                                      Q4 = 22560 J
                      F                     Q = Q1 + Q2 + Q3 + Q4
                                              = 4200 + 66600 + 83720 + 22560
                                            Q = 177080 J Ans




F        3
                 100             100˚ C F                                                         F                    F
         90˚ C (c = 4186 J/kg K, Lv = 2256x103 J/kg)
                                                                                          “                    F
                                                                                                               ”
                 Q1                                        Q2




         100 g                          100 g                           100 g
    100° C                            100° C                          90° C




                                  F                        100 g 100° C                    F                    100 g 100° C
                                      Q1 = mLv
                                         = 0.1x2256x103                             (L     =L         F   )
                                      Q1 = 225600 J
                              F                        100 g 100° C                                            100 g 90° C
                                      Q2 = mc∆T
                                         = 0.1x4186x(100-90)
                                      Q2 = 4186 J
                      F                                F                  Q = Q1 + Q2
                                                                            = 225600 + 4186
                                                                          Q = 229786 J Ans

                                               –                  F             F        www.schoolDD.com                      5
F        4
                     F F                                                          1                 20 ˚C F                 -10 ˚C                                          F
 F                         F            (c                                        = 2100 J/kg K, c = 4186 J/kg K, Lm = 333x103 J/kg)
                                                                                                                                                                   “                F
                                                                                                                                                                                    ”

                               Q1                                                                Q2                                     Q3



       1 kg                                                                       1 kg                                 1 kg                                 1 kg
     20° C                                               0° C
                                                                                                           0° C                                   -10° C

                                                                          F                  1 kg 20° C                                                        1 kg 0° C
                                                                                   Q1 = mc∆T
                                                                                      = 1.0x4186x(20-0)
                                                                                   Q1 = 83720 J
                                                                  F                      1 kg 0° C                                                          1 kg 0° C
                                                                                   Q2 = mLm
                                                                                      = 1.0x333x103                                     (L          =L             )
                                                                                   Q2 = 333000 J
                                                              F                                   1 kg 0° C                                                            1 kg -10° C
                                                                                   Q3 = mc∆T
                                                                                      = 1.0x2100x(0-(-10))
                                                                                   Q3 = 21000 J
                                                 F                                           F                         Q = Q1 + Q2 + Q3
                                                                                                                         = 83720 + 333000 + 21000
                                                                                                                       Q = 437720 J Ans




10.1.6                                       F
                                                                      F                                            F                                                                    F           F
                                                                              F                                             F                                                   F               F
                 F                                        F                          F                         F
                                                     F                                                                          =                       F                                   F


                                                                                         Q =Q                                                 Q    = Q



             F        5
                                    F                    200                                          FF                                     300˚ C F                  1                 20
˚C                              F        F                                                                              F           (              c         = 500 J/kg K, c = 4200 J/kg )

                                                                                         –                 F                    F        www.schoolDD.com                                               6
0.2 kg                                       0.2 kg
                           Q                                            Q
                                                    300° C                                    t° C                                      t ≤ 100° C               F
                                                                                                                                            t     = 300° C                       F
                                                          1 kg                                     1 kg
                                                                                                                                     100° C                              F
                           Q                        20° C               Q                     t° C



                                                   Q =Q
                                         (mc∆T)               = (mc∆T)
F                          F                     t° C        20 < t ≤100
            F           F 0.2x500x(300- t) = 1.0x4200x(t-20)
                             30000 - 100 t = 4200t – 84000
                                            114000 = 4300t
                                                          t =        26.5° C         Ans             (                 )

        F           6
                                     F       5 F                               F              2                                                      0.5
    F                            F

                                                          2 kg                                     2 kg
                         Q                                            Q
                                                  300° C                                    t° C                                    t ≤ 100° C               F
                                                                                                                                        t       = 300° C                     F
                                                    0.5 kg                                     0.5 kg
                                                                      Q                                                          100° C                              F
                         Q                        20° C                                     t° C



                                                   Q =Q
                                         (mc∆T)               = (mc∆T)
F                          F                     t° C        20 < t ≤100
            F           F 2.0x500x(300- t) = 0.5x4200x(t-20)
                             30000 - 100 t = 2100t – 42000
                                            342000 = 3100t
                                                 t = 110.3° C                             > 100° C                 F                                  F
                             F                100° C                                                             F F

                                           2 kg                                                                                  2 kg
                Q                                                         Q                                                100° C
                             300° C


                                         0.5 kg                                    0.5 kg                                    +
                Q            20° C                        Q      1          100° C                   Q       2
                                                                                                                           100° C




                                                              –                       F                  F        www.schoolDD.com                                                   7
F                      F
                                         Q =Q
                                 (mc∆T)               = (mc∆T)           1       + (mL)                2
                F           F 2.0x500x(300-100) = 0.5x4200x(100-20) + mx2256x103
                                      32000 = 2256x103
                                           m = 0.014 kg
                              0.014 kg 100° C                                       F F                    0.5 0.014 = 0.486                   kg      100° C    Ans


        F               7
                                                        1                                 2                                             20˚ C F        FF                 1
                                  200 ˚C                                                           F               F       (                    c           = 1000 J/kg K, c
= 4200 J/kg                       c        = 400 J/kg K )

                                                      1 kg                                        1 kg
                             Q          200° C
                                                             Q                    t° C



                                                      1 kg                                        1 kg
                                                                                  t° C                                         20       < t ≤ 100° C         F
                                       20° C                 Q
                             Q

                                           2 kg                                      2 kg
                                       20° C                 Q                    t° C




                                           Q =Q
                                 (mc∆T)                = (mc∆T)                    + (mc∆T)
    F                          F                     t° C        20 < t ≤100
                    F       F 1.0x400x(200- t) = 1.0x1000x(t-20) + 2.0x4200x(t-20)
                                 80000 - 400 t = 1000t – 20000 + 8400 t - 168000
                                      268000 = 9800t
                                           t = 27.35° C Ans                                   (                        )



            F       8
                     F        200                                    1                                          30 ˚C               F               100
                   0 ˚C                                          F                                         (               c    F       = 800 J/kg K, c = 4200 J/kg K,
L               = 333x103 J/kg )


                                                      –                      F                F                www.schoolDD.com                                                8
1 kg                                        1 kg
                                               30° C              Q                    t° C

                             Q
                                                F 0.2 kg                                F 0.2 kg                                       0   < t < 30° C
                                              30° C               Q   F
                                                                                      t° C




                                                                                         0.1 kg                               0.1 kg
                                                         0.1 kg
                               Q                                  Q                   0° C                  Q              t° C
                                              0° C




                                                                      Q =Q
                                       (mc∆T)               + (mc∆T)           F     = (mL)                + (mc∆T)
F                          F                      t° C        0 < t < 30
        F               F 1.0x4200x(30- t) + 0.2x800x(30- t) = 0.1x333x103 + 0.1x4200x(t-0)
                                               4360x(30- t) = 33300 + 420t
                                                                  97500 = 4780t
                                                                              t =     20.4° C             Ans       (             )

    F               9
                         F            1          100 ˚C F                                                       200                               F
                F   (               c = 500 J/kg K, c = 4200 J/kg K, L                                           = 333x103 J/kg )


                                    1 kg                                      1 kg
                    Q         100° C            Q                  t° C


                                                                                                                                       0   < t < 100° C
                                                                      0.2 kg                                    0.2 kg
                                     0.2 kg
                    Q                           Q                 0° C
                                                                                        Q                    t° C
                             0° C




                                        Q =Q
                              (mc∆T)                 = (mL)               + (mc∆T)
F                          F                     t° C        0 < t < 100
                                                       3
            F           F 1.0x500x(100- t) = 0.2x333x10 + 0.2x4200x(t-0)
                             50000 - 500t = 66600 + 840t
                                  -16600 = 1340t
                                                     –                    F                  F          www.schoolDD.com                                  9
t =             -12.39° C                              F                             F                    F            0° C
                                                   F
                                                           F               F

                                               1 kg                                                                   1 kg
                          Q          100° C                            Q                             0° C




                                                   0.2 kg                                                             +
                          Q         0° C
                                                                       Q                            0° C



                                                                                                    Q =Q
                                    (mc∆T)                             = (mL)
         F                F 1.0x500x(100- 0) = mx333x103
                                     50000 = 333x103m
                                        m = 0.15 kg = 150 g < 200 g OK
             F                    F     0° C                  0.15 kg                                                                           Ans


10.1.7                    F                            F
                      3
                 1.                        F
                               - F                                                              F                 F                             F                    F                               F
                                     F                                                      F         F

                 2.                            F
                              - F                                                       F                                                                                         F          F           F
                                F                                              F                              F                   F                          F                   F F
                                                                                   FF                                                  F                         F           F

                 3.             F                              F
                              - F                                                   F                                     F                 F            F                             F         F
                                                                   F




                                                                       –                                  F                   F       www.schoolDD.com                                                       10
10.2     F
    -        F                                       F                                  F F                                   F                                F
                             F                                                                                                              F

10.2.1                                   F
                                 F                           F                                                F
                                                                                                                                                 P



                                                                                                    T
                                                                     V                           PV = F


10.2.2                   F
                                     F                           F                                                F
                                                                                                              V



                                                                                   P
                                             V           T
                                                                                  = F                                                                T




10.2.3               F
                                                 F                        F                                           F

                                                                     V


                                                                         = F



                                                                                                                                        F        F                         F
                 F                                                       =                        1                       2                     (T F               )

                                                                                                      F                   F P, V F          F =          F F           F       F T
                                                                                                          F                       K F




                                                         –                    F          F    www.schoolDD.com                                                                 11
F

                                                 F                               n                  n=                                                F           =
                                                                                                                                                                                                  1


                                                                 =                                                                                            F           F                               F           1   2
                  F
                                                                                                                                    F             (T F                                )



                                                                                                                               F
                                 PV             = nRT                                                       R= F                        F = 8.31 J/mol K



                                                                         .                              F

                               n=
                                                                                                   = 6.02 x 1023

         F 1                                                                         F             6.02x1023

                  F       PV =                  RT


 F            F           KB =                  =            F                                              F          F   =                                      =           1.38x10-23 J/K
                      F   PV = NKB T


                           PV = nRT                                  PV = NKB T                                                                 F F                   F                       F

                                    F                            F                           F F
1.                                                                           F           PV = nRT

2.                                          F            F                       F       P          T, P           n, V                 T, V                          n               P                           F
3.                                      F            F                   F                                                 F                F                                 1           2                   F               F F
          F                F
                                                                                                    = R                                 = R


                                                                                                    =                              (P                     F           P           F   )

     F                                                               F
                                                                                         –                         F                    F                     www.schoolDD.com                                                      12
F           10
                    F                                      1                F                    2 x 105 Pa                 7˚ C F F   F F
                2                    F                                                    F         F

                                         V 1 = 1 m3                                                            V 2 = 2 m3
                                         P1 = 2x105 Pa                                                         P2 = P 1
                                         T1 = 273+7 = 280 K                                                    T2 = ?
                                         n1                                                                    n2 = n1


                         F       PV = nRT
F                                        F 2
                                                           =


                P                n
                                               F           =


                                                           =


                                                   T2 = 560 K                   560 273 = 287° C Ans

            F       11
                    F                                  F       105 Pa                 F                       27˚ C          -3˚ C
    F

                    V1                                                                             V2 = V1
                    P1 = 2x105 Pa                                                                  P2 = ?
                    T1 = 273+27= 300 K                                                             T2 = 273+(-3) = 270 K
                    n1                                                                             n2 = n1

                             F   PV = nRT
F                                        F 2
                                                           =


                V                n

                                                   –                    F         F           www.schoolDD.com                               13
F            =


                                                           =


                                                      P2 = 0.9x105 Pa Ans

             F       12
                                  F               F            F         17˚ C                         F 2 x 105 Pa                   F
                 F                    27˚ C                                             F             F (
=105 Pa)

                                  V1                                                          V2 = V1
                                  Pg1 = 2x105 Pa                                              Pg2 = ?
                                  T1 = 273+17= 290 K                                          T2 = 273+27 = 300 K
                                  n1                                                          n2 = n1


                          F   PV = nRT
 F                                     F 2
                                                           =


                     V        n
                                              F            =


                                                           =                                    F P        FF             P   F   F


                                                           =


                                                  Pg 2 = 2.09x105 Pa Ans

         F           13
                     F                                10               27˚ C                105 Pa                    F
     F


                                                      –            F      F      www.schoolDD.com                                         14
V = 10
                              P = 105 Pa
                              T = 273+27 = 300 K
                              n=?
                              m=?


                       F     PV = nRT
 F                F       F           F
         F        F 105(10x10-3) = n (8.31)(300)                     1           = 1000 cc = 1000 cm3 = 1000(10-6 m3) = 10-3 m3
                              n = 103/ 2493 = 0.4                            Ans
                 n=          m = nM
                                 = 0.4x2.0x10-3

                                        m = 8.0x10-4 kg Ans

     F     14
             F                               50                              F                       10                           27˚ C
  F      F F         F                  5                                                   17˚ C                F   F F
( R = 8.31 J/mol K, MN2 = 28 g/mol, 1 atm = 105 Pa )
                           V1 = 50x10-3 m3                                                 V2 = 50x10-3 m3
                           P1 = 10 atm                                                     P2 = 5 atm
                           T1 = 273+27 = 300 K                                             T2 = 273+17 = 290 K
                           n1 = ?                                                          n2 = ?


             .        n1      F              F       P1 V1 = n1RT1
                                        10x105x50x10-3 = n1x8.31x300
                                                    n1 = 20
             .        n2      F               F P2 V2 = n2RT2
                                        5x10 x50x10-3 = n2x8.31x290
                                            5

                                                  n2 = 10.4
                                  F F     F n1 n2 = 20 10.4 = 9.6                             9.6x28x10-3 = 0.27 kg Ans




                                                 –           F           F        www.schoolDD.com                                   15
F               15
                             F           64                27˚ C                              20   F   F
                  F        ( R = 8.31 J/mol K, MO2 = 28 g/mol )
                           m = 64 g
                           T = 273+27 = 300 K
                           V = 20x10-3 m3
                           P=?


                      P       F                F PV = nRT
                                            Px20x10-3 = x8.31x300                 n=
                                                   P = 2.493x105 Pa        Ans

          F       16
              F                   1                1.3             0˚ C             1
      13                               10                 27˚ C

                            V1 = 1                                         V2 = 10
                            m1 = 1.3 g                                     m2 = 13 g
                            T1 = 273+0 = 273 K                             T2 = 273+27 = 300 K
                            P1 = 1 atm                                     P2 = ?

                       F     PV = nRT
F                                     F 2
                                                     =
    F n=                          M

                                        F            =


                                                     =


                                                   P2 = 1.10 atm Ans




                                               –             F         F   www.schoolDD.com                16
F       17
              F                                        F F                                                                 F
                F


                                V1                                                       V2 = V1
                                P1                                                       P2 = ½ P 1
                                T1                                                       T2 = T1
                                n1                                                       n2 = ?


                    F                PV = nRT
F                                        F 2
                                                             =
    F V             T

                                                   F         =


                                                             =
                                                           n2 = ½ n1 Ans

          F   18
                                               F                 F 10 kg/m3             27˚ C            2             F       F
                            F                              17˚ C        1                F                     F   F


                                V1                                                       V2 = V1
                                T1 = 273+27 = 300 K                                      T2 = 273+17 = 290 K
                                P1 = 2 atm                                               P2 = 1 atm
                                              3
                                  1 = 10 kg/m                                              2=?




                        F            PV = nRT
F                                        F 2
                                                             =
    F n=                             M

                                                       –            F         F   www.schoolDD.com                                 17
F                           =


                                                                       =


                                                               =


                                                               =


                                                                           = 5.17 kg/m3 Ans

10.3           F                       F
10.3.1                                         F
          F
              1.                   F                               F                                            F
                                                         F F                                                        F
              2.                                               F                                                            F                   F
              3.                                                                           F                            F               F   F

10.3.2                         F                                           ( < EK > )
                           F                                                     F < EK >                   F                       F
    1                  F                               (J)

                                       < EK > =                                KB T


                   F                                      F N          F                           N< EK >
                                                       N< EK > = NKB T
                                                               = PV (                                   PV = NKB T )
                                                               = nRT (                                  PV = nRT )

-        < EK >                                    F                                 F F            F                           F




                                                         –                       F             F          www.schoolDD.com                          18
10.3.3                                                                  F
                                                                    F                 F            F                                                vrms   (vroot mean square )
      F                             F                   (m/s)


                                                        vrms =                                                              M=             F 1   (kg)




     -                                  vrms                F               T             M
     -            vrms         F F                                                  (v)       F F          F

          F           19
                               F                            20                                                         27˚ C ( R = 8.31 J/mol K, MH2 = 2 g/mol )

                  .                                 F                                                  F
                  .                             F               F
                  .    vrms                                                     F


                                               m = 20 g
                                               T = 273+27 = 300 K



 .   < EK > = ?
          < EK > =                      KB T                                                  KB =                 =               = 1.38x10-23
                           =            x 1.38x10-23x300
      < EK >               = 6.21x10-25 J Ans

 .   N< EK > = ?
              .                N               N = n NA
                                                        =               =             x 6.02x1023

                                               N = 6.02x1024
                                   N< EK > =                    6.02x1024x 6.21x10-25 = 3.73 J Ans


                                                                –                              F               F        www.schoolDD.com                                   19
.   vrms = ?

     vrms =


              =                        =

     vrms = 1933.78 m/s Ans


      F       20
                                   F                               F                                F 3            10              2 Pa

                    n=3
                    V = 10 = 10x10-3 m3
                    P = 2 Pa
                    N<EK> = ?
                    <EK> = ?
          .          N         N = n NA = 3x6.02x1023
                      F                    F               N< EK > =             NKBT =         PV        ( PV = NKBT)
                                                                                               -3
                                                                            =    x2x10x10
                                                       N< EK >              = 3x10-2 J Ans
                      F                            < EK >                  < EK > =                 =


                                                                       < EK >           = 1.66x10-26 J Ans
      F       21
              F                                        F                        2x 1025              F         F          105 Pa
                F                              F


                    N/V = 2x1025               /m3
                    P = 1x105 Pa
                    <EK> = ?

                      F                            < EK >                  < EK > =         KBT
                                                               F   N< EK >              =   NKBT =        PV       ( PV = NKBT)
                                                                           < EK >       =
                                                                                        = x
                                                                           < EK >       = 7.5x10-21 J Ans

                                                   –                   F            F       www.schoolDD.com                              20
F                22
                                           F
                     .                                  F F           2 F                   F                             F
                     .                                   F F                    2 F                  F                           F

.

                              T1                                                      T2 = 2 T1
                              <EK1>                                                   <EK2> = ?


                     < EK > =                  KBT
            F        < EK >               T
                                    =           =


                    < EK2 >         =     2< EK1 >              Ans

.
                              V1                                                      V2 = V1
                              P1                                                      P2 = 2 P 1
                              N1                                                      N2 = N1
                              <EK1>                                                   <EK2> = ?

                     < EK > =                  KBT
                    N< EK >           =        NKBT =           PV
                F    < EK >               P             N         V
                                    =           =


                    < EK2 >         =     2< EK1 >              Ans

        F                23
                              F A                   1                    7˚ C               F B             2                 27˚ C
                          F           F                 F       ( R = 8.31 J/mol K )

                         nA = 1                                                                   nB = 2
    A                    TA = 273 + 7 = 280 K                      +                  B           TB = 273 + 27 = 300 K
                         <EKA>                                                                    <EKB>


                                                            –               F         F     www.schoolDD.com                          21
N< EK >                      N< EK > =              NKBT
                                                  =    nRT

               (N< EK >)A + (N< EK >)B = ( nRT)A + ( nRT)B
                                                  =     R(nATA + nBTB)

                                                  =     x8.31(1x280 + 2x300)
                                     F            =   1.097x104 J              Ans

           F      24
                                              F                            F             F         ( MH2 = 2 g/mol, MO2 =
32 g/mol)



       H2
                   vrmsH2                O2
                                                      vrmsO2



       vrms =
               F vrms                    T

                            =            =             = 4


                 vrmsH2 = 4 vrmsO2           Ans

           F      25
                  F                                                F                 F             4 F
vrms                    F


                                                         =4
                   vrms1                              vrms2


       vrms =
               PV = nRT
       F       RT =

                 vrms =
                                         –                     F       F        www.schoolDD.com                      22
=                                                               =           =


         F vrms                                               P

                            =                             =                 = 2


          vrms2 = 2 vrms1                                         Ans

10.4
    -
    -               F                                                          FF                           F         F
                                                                      F        U                                                          F       F
                                    F                                          F                        F                         F           F
            F F                                                                         F                       F F                   F               F
                        F                                     F


                                            U = N< EK >

                                F            FF       U =                 NKBT
                                                              =           nRT
                                                                  =       PV




10.4.1          F           1                         F                        F
                                        F         F                        F F


         〉 ∆W
                                                                                    ∆Q = ∆U + ∆W
                            〉 ∆U

                                                  〉 ∆Q
                                                                                                                          ΔW   = FΔs
                                                                                                                               = PAΔs
                                                                                                                               = PΔV


                                                                  –                         F       F           www.schoolDD.com                          23
F               F F                                                      +
             ∆Q
                                                F                                                                    -
                                                                                                                     +
             ∆U
                                                                                                                     -
                                                                                                                     +
             ∆W
                                    F                                                                                -

    F         26
              F         F               F                             1000 J         F                F          F           200 J                 F
F                   F                                             F

                   ∆W = ?
                   〉 ∆U = 200 J

                   〉 ∆Q = 1000 J




     ∆Q = ∆U + ∆W
    1000 = 200 + ∆W
    ∆W = 800
                                F                   F       =     800 J      (           ∆W      + ) Ans

    F         27
              F             1024           F F                             F F                            1˚ C       F   F           F   F F   F
                        (KB = 1.38x10-23 )

                     N = 1024
                    ∆T = 1
                    ∆V = 0


                   〉 ∆Q = ?




            ∆Q = ∆U + ∆W
                   =        NKB∆T + P∆V
               = x1024x1.38x10-23x1 + 0
            ∆Q = 20.7
        F      F            F       F F     ∆Q = 20.7 J                    Ans       (∆Q         +)
                                                        –              F         F        www.schoolDD.com                                             24
F            28
                                100 N                                                                 F             1           F            1K
                                                        F       F       F                                    F 20 cm. ( R = 8.31 J/mol K )

  F = 100 N
                             n=1
                            ∆T = 1 K
0.20                        ∆Q = ?




               ∆Q = ∆U + ∆W
                        =       nR∆T + (-F∆s)                       (             F                           )
                        =       x1x8.31x1 – 100x0.20
               ∆Q = -7.5                        (                   F                             )
                                           F                    ∆Q =        7.5 J           Ans



       F            29
                F           F         F             F       F                         F F


                         P
∆W
∆U                       ∆V

                        〉 ∆Q = ?




               ∆Q = ∆U + ∆W
                        =       NKB∆T + P∆V
                        =       P∆V + P∆V                               (        PV = NKBT)
               ∆Q =                 P∆V

           F        F           F         F F       ∆Q =            P∆V J             Ans




                                                        –                    F               F            www.schoolDD.com                        25
F         30
                         F           F           F                     20                    27˚ C         105 Pa     F
                                                                   57˚ C                                 F F      F   F F   F

                     V1 = 20
                     T1 = 273 + 27 = 300 K                                           V2 = ?
                                                                           ∆W        T2 = 273 + 57 = 330 K
                     P1 = 105 Pa
                                                                           ∆U        P2 = P1

                 〉 ∆Q = ?




V2               F                        =
         P                       n
                             F            =
                                          =
                                     V2   = 22
        ∆Q = ∆U + ∆W
                     =           NKB∆T + P∆V
                     =           P∆V + P∆V                     (           PV = NKBT)
           =   P∆V =                                 x10 x(22-2)x10-3
                                                         5

        ∆Q = 500
    F        F                   F       F F   ∆Q =                J       Ans




                                                     –                 F         F   www.schoolDD.com                           26

10ความร้อน

  • 1.
    SchoolDD.com 10 www.schoolDD.com
  • 2.
    10 10.1 F F F F F (Q) F (J) - F 1 (= 4.186 J ) F F 1 1° C 10.1.1 F F F F F F F F F F 10.2.1 F F F F F F F F F F F F F F F F F 1. (° C) 2. (K) F F FF F F F ( F SI) K °C 373.16 100 F F K = C + 273 273.16 0 F C= R= F = = F= F K= – F F www.schoolDD.com 1
  • 3.
    10.1.2 F 1. F (C) F F F F F (J/K) 〉 ∆T m C= ∆Q 2. F (c ) F F 1 F F F F (J/kg K) 〉 ∆T m ∆Q c= F FF F F m ΔT F F Q= F (J) m= (kg) Q = mc∆T c= F (J/kg K) ΔT = (K ˚C) - F (C) F F F C F C F - F (c) F F F c (J/kg K) 4186 (-10˚C 0˚C) 2100 900 450 390 140 130 – F F www.schoolDD.com 2
  • 4.
    F 1 F F 100 25˚C ( c = 390 J/kg K) . 45 ˚C . 15 ˚C . F F F F F Q = mc∆T = 0.10x390x(45-25) Q = 780 J Ans . F F F Q = mc∆T = 0.10x390x(25-15) Q = 390 J Ans 10.1.4 F F F F F F F F F s - F F F F F F F F 10.1.5 F 3 F F F F F F F F F F F F F F F F F F F F F F F F F F F F – F F www.schoolDD.com 3
  • 5.
    F F F F F F F F m F F F Q= F (J) Q = mL m= (kg) L= F (J/kg) F F Lm (J/kg) Lv (J/kg) 333x103 2256x103 58.6x103 452x103 5.23x103 20.9x103 F 2 F F 200 -10˚ C F F 190 ( c = 2100 J/kg K, c = 3 3 4186 J/kg K, Lm = 333x10 J/kg, Lv = 2256x10 J/kg ) “ F F F F F F F F ” Q1 Q2 Q3 Q4 200 g 200 g 200 g 200 g 190 g + 10 g -10° C 0° C 0° C 100° C 100° C – F F www.schoolDD.com 4
  • 6.
    F F 200 g -10° C 0° C Q1 = mc∆T = 0.2x2100x(0-(-10)) Q1 = 4200 J F F 200 g 0° C 0° C Q2 = mL = 0.2x333x103 Q2 = 66600 J F F 200 g 0° C 100° C Q3 = mc∆T = 0.2x4186x(100-0) Q3 = 83720 J F F 10 g 100° C 10 g 100° C Q4 = mL = 0.01x2256x103 Q4 = 22560 J F Q = Q1 + Q2 + Q3 + Q4 = 4200 + 66600 + 83720 + 22560 Q = 177080 J Ans F 3 100 100˚ C F F F 90˚ C (c = 4186 J/kg K, Lv = 2256x103 J/kg) “ F ” Q1 Q2 100 g 100 g 100 g 100° C 100° C 90° C F 100 g 100° C F 100 g 100° C Q1 = mLv = 0.1x2256x103 (L =L F ) Q1 = 225600 J F 100 g 100° C 100 g 90° C Q2 = mc∆T = 0.1x4186x(100-90) Q2 = 4186 J F F Q = Q1 + Q2 = 225600 + 4186 Q = 229786 J Ans – F F www.schoolDD.com 5
  • 7.
    F 4 F F 1 20 ˚C F -10 ˚C F F F (c = 2100 J/kg K, c = 4186 J/kg K, Lm = 333x103 J/kg) “ F ” Q1 Q2 Q3 1 kg 1 kg 1 kg 1 kg 20° C 0° C 0° C -10° C F 1 kg 20° C 1 kg 0° C Q1 = mc∆T = 1.0x4186x(20-0) Q1 = 83720 J F 1 kg 0° C 1 kg 0° C Q2 = mLm = 1.0x333x103 (L =L ) Q2 = 333000 J F 1 kg 0° C 1 kg -10° C Q3 = mc∆T = 1.0x2100x(0-(-10)) Q3 = 21000 J F F Q = Q1 + Q2 + Q3 = 83720 + 333000 + 21000 Q = 437720 J Ans 10.1.6 F F F F F F F F F F F F F F = F F Q =Q Q = Q F 5 F 200 FF 300˚ C F 1 20 ˚C F F F ( c = 500 J/kg K, c = 4200 J/kg ) – F F www.schoolDD.com 6
  • 8.
    0.2 kg 0.2 kg Q Q 300° C t° C t ≤ 100° C F t = 300° C F 1 kg 1 kg 100° C F Q 20° C Q t° C Q =Q (mc∆T) = (mc∆T) F F t° C 20 < t ≤100 F F 0.2x500x(300- t) = 1.0x4200x(t-20) 30000 - 100 t = 4200t – 84000 114000 = 4300t t = 26.5° C Ans ( ) F 6 F 5 F F 2 0.5 F F 2 kg 2 kg Q Q 300° C t° C t ≤ 100° C F t = 300° C F 0.5 kg 0.5 kg Q 100° C F Q 20° C t° C Q =Q (mc∆T) = (mc∆T) F F t° C 20 < t ≤100 F F 2.0x500x(300- t) = 0.5x4200x(t-20) 30000 - 100 t = 2100t – 42000 342000 = 3100t t = 110.3° C > 100° C F F F 100° C F F 2 kg 2 kg Q Q 100° C 300° C 0.5 kg 0.5 kg + Q 20° C Q 1 100° C Q 2 100° C – F F www.schoolDD.com 7
  • 9.
    F F Q =Q (mc∆T) = (mc∆T) 1 + (mL) 2 F F 2.0x500x(300-100) = 0.5x4200x(100-20) + mx2256x103 32000 = 2256x103 m = 0.014 kg 0.014 kg 100° C F F 0.5 0.014 = 0.486 kg 100° C Ans F 7 1 2 20˚ C F FF 1 200 ˚C F F ( c = 1000 J/kg K, c = 4200 J/kg c = 400 J/kg K ) 1 kg 1 kg Q 200° C Q t° C 1 kg 1 kg t° C 20 < t ≤ 100° C F 20° C Q Q 2 kg 2 kg 20° C Q t° C Q =Q (mc∆T) = (mc∆T) + (mc∆T) F F t° C 20 < t ≤100 F F 1.0x400x(200- t) = 1.0x1000x(t-20) + 2.0x4200x(t-20) 80000 - 400 t = 1000t – 20000 + 8400 t - 168000 268000 = 9800t t = 27.35° C Ans ( ) F 8 F 200 1 30 ˚C F 100 0 ˚C F ( c F = 800 J/kg K, c = 4200 J/kg K, L = 333x103 J/kg ) – F F www.schoolDD.com 8
  • 10.
    1 kg 1 kg 30° C Q t° C Q F 0.2 kg F 0.2 kg 0 < t < 30° C 30° C Q F t° C 0.1 kg 0.1 kg 0.1 kg Q Q 0° C Q t° C 0° C Q =Q (mc∆T) + (mc∆T) F = (mL) + (mc∆T) F F t° C 0 < t < 30 F F 1.0x4200x(30- t) + 0.2x800x(30- t) = 0.1x333x103 + 0.1x4200x(t-0) 4360x(30- t) = 33300 + 420t 97500 = 4780t t = 20.4° C Ans ( ) F 9 F 1 100 ˚C F 200 F F ( c = 500 J/kg K, c = 4200 J/kg K, L = 333x103 J/kg ) 1 kg 1 kg Q 100° C Q t° C 0 < t < 100° C 0.2 kg 0.2 kg 0.2 kg Q Q 0° C Q t° C 0° C Q =Q (mc∆T) = (mL) + (mc∆T) F F t° C 0 < t < 100 3 F F 1.0x500x(100- t) = 0.2x333x10 + 0.2x4200x(t-0) 50000 - 500t = 66600 + 840t -16600 = 1340t – F F www.schoolDD.com 9
  • 11.
    t = -12.39° C F F F 0° C F F F 1 kg 1 kg Q 100° C Q 0° C 0.2 kg + Q 0° C Q 0° C Q =Q (mc∆T) = (mL) F F 1.0x500x(100- 0) = mx333x103 50000 = 333x103m m = 0.15 kg = 150 g < 200 g OK F F 0° C 0.15 kg Ans 10.1.7 F F 3 1. F - F F F F F F F F F 2. F - F F F F F F F F F F F F FF F F F 3. F F - F F F F F F F F – F F www.schoolDD.com 10
  • 12.
    10.2 F - F F F F F F F F 10.2.1 F F F F P T V PV = F 10.2.2 F F F F V P V T = F T 10.2.3 F F F F V = F F F F F = 1 2 (T F ) F F P, V F F = F F F F T F K F – F F www.schoolDD.com 11
  • 13.
    F F n n= F = 1 = F F F 1 2 F F (T F ) F PV = nRT R= F F = 8.31 J/mol K . F n= = 6.02 x 1023 F 1 F 6.02x1023 F PV = RT F F KB = = F F F = = 1.38x10-23 J/K F PV = NKB T PV = nRT PV = NKB T F F F F F F F F 1. F PV = nRT 2. F F F P T, P n, V T, V n P F 3. F F F F F 1 2 F F F F F = R = R = (P F P F ) F F – F F www.schoolDD.com 12
  • 14.
    F 10 F 1 F 2 x 105 Pa 7˚ C F F F F 2 F F F V 1 = 1 m3 V 2 = 2 m3 P1 = 2x105 Pa P2 = P 1 T1 = 273+7 = 280 K T2 = ? n1 n2 = n1 F PV = nRT F F 2 = P n F = = T2 = 560 K 560 273 = 287° C Ans F 11 F F 105 Pa F 27˚ C -3˚ C F V1 V2 = V1 P1 = 2x105 Pa P2 = ? T1 = 273+27= 300 K T2 = 273+(-3) = 270 K n1 n2 = n1 F PV = nRT F F 2 = V n – F F www.schoolDD.com 13
  • 15.
    F = = P2 = 0.9x105 Pa Ans F 12 F F F 17˚ C F 2 x 105 Pa F F 27˚ C F F ( =105 Pa) V1 V2 = V1 Pg1 = 2x105 Pa Pg2 = ? T1 = 273+17= 290 K T2 = 273+27 = 300 K n1 n2 = n1 F PV = nRT F F 2 = V n F = = F P FF P F F = Pg 2 = 2.09x105 Pa Ans F 13 F 10 27˚ C 105 Pa F F – F F www.schoolDD.com 14
  • 16.
    V = 10 P = 105 Pa T = 273+27 = 300 K n=? m=? F PV = nRT F F F F F F 105(10x10-3) = n (8.31)(300) 1 = 1000 cc = 1000 cm3 = 1000(10-6 m3) = 10-3 m3 n = 103/ 2493 = 0.4 Ans n= m = nM = 0.4x2.0x10-3 m = 8.0x10-4 kg Ans F 14 F 50 F 10 27˚ C F F F F 5 17˚ C F F F ( R = 8.31 J/mol K, MN2 = 28 g/mol, 1 atm = 105 Pa ) V1 = 50x10-3 m3 V2 = 50x10-3 m3 P1 = 10 atm P2 = 5 atm T1 = 273+27 = 300 K T2 = 273+17 = 290 K n1 = ? n2 = ? . n1 F F P1 V1 = n1RT1 10x105x50x10-3 = n1x8.31x300 n1 = 20 . n2 F F P2 V2 = n2RT2 5x10 x50x10-3 = n2x8.31x290 5 n2 = 10.4 F F F n1 n2 = 20 10.4 = 9.6 9.6x28x10-3 = 0.27 kg Ans – F F www.schoolDD.com 15
  • 17.
    F 15 F 64 27˚ C 20 F F F ( R = 8.31 J/mol K, MO2 = 28 g/mol ) m = 64 g T = 273+27 = 300 K V = 20x10-3 m3 P=? P F F PV = nRT Px20x10-3 = x8.31x300 n= P = 2.493x105 Pa Ans F 16 F 1 1.3 0˚ C 1 13 10 27˚ C V1 = 1 V2 = 10 m1 = 1.3 g m2 = 13 g T1 = 273+0 = 273 K T2 = 273+27 = 300 K P1 = 1 atm P2 = ? F PV = nRT F F 2 = F n= M F = = P2 = 1.10 atm Ans – F F www.schoolDD.com 16
  • 18.
    F 17 F F F F F V1 V2 = V1 P1 P2 = ½ P 1 T1 T2 = T1 n1 n2 = ? F PV = nRT F F 2 = F V T F = = n2 = ½ n1 Ans F 18 F F 10 kg/m3 27˚ C 2 F F F 17˚ C 1 F F F V1 V2 = V1 T1 = 273+27 = 300 K T2 = 273+17 = 290 K P1 = 2 atm P2 = 1 atm 3 1 = 10 kg/m 2=? F PV = nRT F F 2 = F n= M – F F www.schoolDD.com 17
  • 19.
    F = = = = = 5.17 kg/m3 Ans 10.3 F F 10.3.1 F F 1. F F F F F F 2. F F F 3. F F F F 10.3.2 F ( < EK > ) F F < EK > F F 1 F (J) < EK > = KB T F F N F N< EK > N< EK > = NKB T = PV ( PV = NKB T ) = nRT ( PV = nRT ) - < EK > F F F F F – F F www.schoolDD.com 18
  • 20.
    10.3.3 F F F F vrms (vroot mean square ) F F (m/s) vrms = M= F 1 (kg) - vrms F T M - vrms F F (v) F F F F 19 F 20 27˚ C ( R = 8.31 J/mol K, MH2 = 2 g/mol ) . F F . F F . vrms F m = 20 g T = 273+27 = 300 K . < EK > = ? < EK > = KB T KB = = = 1.38x10-23 = x 1.38x10-23x300 < EK > = 6.21x10-25 J Ans . N< EK > = ? . N N = n NA = = x 6.02x1023 N = 6.02x1024 N< EK > = 6.02x1024x 6.21x10-25 = 3.73 J Ans – F F www.schoolDD.com 19
  • 21.
    . vrms = ? vrms = = = vrms = 1933.78 m/s Ans F 20 F F F 3 10 2 Pa n=3 V = 10 = 10x10-3 m3 P = 2 Pa N<EK> = ? <EK> = ? . N N = n NA = 3x6.02x1023 F F N< EK > = NKBT = PV ( PV = NKBT) -3 = x2x10x10 N< EK > = 3x10-2 J Ans F < EK > < EK > = = < EK > = 1.66x10-26 J Ans F 21 F F 2x 1025 F F 105 Pa F F N/V = 2x1025 /m3 P = 1x105 Pa <EK> = ? F < EK > < EK > = KBT F N< EK > = NKBT = PV ( PV = NKBT) < EK > = = x < EK > = 7.5x10-21 J Ans – F F www.schoolDD.com 20
  • 22.
    F 22 F . F F 2 F F F . F F 2 F F F . T1 T2 = 2 T1 <EK1> <EK2> = ? < EK > = KBT F < EK > T = = < EK2 > = 2< EK1 > Ans . V1 V2 = V1 P1 P2 = 2 P 1 N1 N2 = N1 <EK1> <EK2> = ? < EK > = KBT N< EK > = NKBT = PV F < EK > P N V = = < EK2 > = 2< EK1 > Ans F 23 F A 1 7˚ C F B 2 27˚ C F F F ( R = 8.31 J/mol K ) nA = 1 nB = 2 A TA = 273 + 7 = 280 K + B TB = 273 + 27 = 300 K <EKA> <EKB> – F F www.schoolDD.com 21
  • 23.
    N< EK > N< EK > = NKBT = nRT (N< EK >)A + (N< EK >)B = ( nRT)A + ( nRT)B = R(nATA + nBTB) = x8.31(1x280 + 2x300) F = 1.097x104 J Ans F 24 F F F ( MH2 = 2 g/mol, MO2 = 32 g/mol) H2 vrmsH2 O2 vrmsO2 vrms = F vrms T = = = 4 vrmsH2 = 4 vrmsO2 Ans F 25 F F F 4 F vrms F =4 vrms1 vrms2 vrms = PV = nRT F RT = vrms = – F F www.schoolDD.com 22
  • 24.
    = = = F vrms P = = = 2 vrms2 = 2 vrms1 Ans 10.4 - - F FF F F F U F F F F F F F F F F F F F F F F U = N< EK > F FF U = NKBT = nRT = PV 10.4.1 F 1 F F F F F F 〉 ∆W ∆Q = ∆U + ∆W 〉 ∆U 〉 ∆Q ΔW = FΔs = PAΔs = PΔV – F F www.schoolDD.com 23
  • 25.
    F F F + ∆Q F - + ∆U - + ∆W F - F 26 F F F 1000 J F F F 200 J F F F F ∆W = ? 〉 ∆U = 200 J 〉 ∆Q = 1000 J ∆Q = ∆U + ∆W 1000 = 200 + ∆W ∆W = 800 F F = 800 J ( ∆W + ) Ans F 27 F 1024 F F F F 1˚ C F F F F F F (KB = 1.38x10-23 ) N = 1024 ∆T = 1 ∆V = 0 〉 ∆Q = ? ∆Q = ∆U + ∆W = NKB∆T + P∆V = x1024x1.38x10-23x1 + 0 ∆Q = 20.7 F F F F F ∆Q = 20.7 J Ans (∆Q +) – F F www.schoolDD.com 24
  • 26.
    F 28 100 N F 1 F 1K F F F F 20 cm. ( R = 8.31 J/mol K ) F = 100 N n=1 ∆T = 1 K 0.20 ∆Q = ? ∆Q = ∆U + ∆W = nR∆T + (-F∆s) ( F ) = x1x8.31x1 – 100x0.20 ∆Q = -7.5 ( F ) F ∆Q = 7.5 J Ans F 29 F F F F F F F P ∆W ∆U ∆V 〉 ∆Q = ? ∆Q = ∆U + ∆W = NKB∆T + P∆V = P∆V + P∆V ( PV = NKBT) ∆Q = P∆V F F F F F ∆Q = P∆V J Ans – F F www.schoolDD.com 25
  • 27.
    F 30 F F F 20 27˚ C 105 Pa F 57˚ C F F F F F F V1 = 20 T1 = 273 + 27 = 300 K V2 = ? ∆W T2 = 273 + 57 = 330 K P1 = 105 Pa ∆U P2 = P1 〉 ∆Q = ? V2 F = P n F = = V2 = 22 ∆Q = ∆U + ∆W = NKB∆T + P∆V = P∆V + P∆V ( PV = NKBT) = P∆V = x10 x(22-2)x10-3 5 ∆Q = 500 F F F F F ∆Q = J Ans – F F www.schoolDD.com 26