fundamentals of algebra

1. An aqueous solution has 5% urea and 10% glucose by weight. What Will be
the freezing point of this solution? (Kf water = 1.86 K kg mole–1)
Ans. (……. )
Example
Solution
-
3.04

2. Henry's constant of four gases A, B, C and D in waler are 40.3, 1.67, 0.413
and 0.611 bar at 298 K and 1 atm. The gas which has maximum solubility in
water at 298 K and 1 atm is
(1) A (2) 8 (3) C (4) D
Ans. (……..)
Example
Solution
(3)

3. 6 g of non volatile, non-electrolytic solute X is present in 1 litre and this solution
is isotonic with 0.2925 (w/v)% NaCl solution.
(Assume NaCl completely dissociates and temperature of both solution is 27 °C).
Molar mass of X (in g/mol) is
(1) 30 (2) 60 {3) 90 (4) 120
Ans. (……..)
Example
Solution
(2)

4. Depression of freezing point of 0.01 molal aqueous CH3COOH solution is
0.0204°C. 1 molal urea solution freezes at –1.86 C. Assuming molality equal
to molarity, pH of CH3COOH solution is
(1) 2 (2) 3 (3) 3.2 (4) 4.2
Ans. (……..)
Example
Solution
HINT [n8] =
ca
(2)

5. What should be the boiling point of 1.0 molal aqueous KCI solution
(assuming complete dissociation of KCI).
(If Kb(H2O) is 0.52 K m–1 )
(1) 101.04°C (2) 98.5°C
(3) 102.5°C (4) 105.2°C
Ans. (……. )
Example
Solution
(1)

6. pH of a 0.1 M monobasic acid is found to be 2. Hence its osmotic pressure at
a given temperature T K is
(1) 0.1 RT (2) 0.11 RT
(3) 1.1 RT (4) 0.01 RT
Ans. (…… )
Example
Solution
(2)

7. The amount of ice that will separate out on cooling a solution containing
50 g of ethylene glycol in 200 g water to –9.3°C is (Kf = 1.86 K/molal)
(1) 38. 71 mg (2) 161.29 g (3) 38.71 g (4) 42 g
Ans. (……. )
Example
Solution
(3)

8. Dry air was passed through a solution of 5g solute in 80g H2O, then
through pure water. The loss in weight if solution was 2.5g that of pure
water 0.04g. What is the value of
𝐋𝐨𝐬𝐬 𝐢𝐧 𝐰𝐭 𝐨𝐟 𝐬𝐨𝐥𝐮𝐭𝐢𝐨𝐧
𝐋𝐨𝐬𝐬 𝐢𝐧 𝐰𝐭 𝐨𝐟 𝐒𝐚𝐥𝐭
=
𝐏𝟎−𝐏𝐒
𝐏𝟓
Ans. (……. )
Example
Solution
⑤
32.25

9. In a solvent 5O% of benzoic acid dimerises while rest ionises, determine
molar mass of acid which is observed and also its Van't Hoff factor.
Ans. (……)
Example
Solution
i =
1.25
Mobs =
97.6gr/mole.

10. Sea water is found to contain 0.2925% NaCl. 0.475% MgCl2 and 0.84% MX
by weight of solution. What is the normal boiling point of sea water if NaCl,
MgCI2 and MX dissociate to 50%, 70% and 30% respectively?
[Given Kb (H2O) = 0.52 K molal–1, molecular mass of MX = 84, B.P. of water
=373.15 K]
Ans. (……. )
Example
Solution
373.61k

11. What weight of solute (mol. wt. 60) is required to dissolve in 180g of water
to reduce the vapour pressure to 4/5th of pure water?
Ans. (……. )
Example
Solution
120
gr

12. Consider the following graphs
Choose the correct statements.
(1) According to both graphs mole fraction of A > mole fraction of B in condensate
(2) Graph I belongs to minimum boiling azeotrope
(3) Graph II belongs to maximum boiling azeotrope
(4) Graph II belongs to minimum boiling azeotrope while graph I belongs to
minimum boiling azeotrope.
V
V
L
L
Temperature
χA= 1
χB= 0
χB= 1
χA= 0
Graph-I
V V
L
L
Temperature
χA= 1
χB= 0
χB= 1
χA= 0
Graph-II
Ans. (……. )
Example
Solution
1,2,3

13. STATEMENT-1 : 0.1 M solution of Na2SO4 has greater osmotic pressure than
0.1 M solution of urea at same temperature.
and
STATEMENT-2 : The value of van’t Hoff factor for Na2SO4 is less than urea.
Ans. (……. )
Example
Solution
Mark the
statement and Fe
T,F

14. STATEMENT-1 : The equivalent mass or Mohr’s salt is
𝐌
𝟒
in non-redox
reaction (If M is molecular mass of Mohr’s salt.)
and
STATEMENT-2 : The normality of Mohr's salt ls higher than molarity for
same amount and volume at constant temperature.
Ans. (……. )
Example
Solution
Mark
the statement
T
andF?
I, F

15. STATEMENT-1 : One molar solution is always more concentrated than one
molal solution.
and
STATEMENT-2 : The amount of solvent in 1 M and 1 m aqueous solution is
not equal.
Ans. (……. )
Example
Solution
Mark the statement TanalF
I,T.

16. STATEMENT-1 : Iodine is more soluble In CCI4 than in water.
and
STATEMENT-2 : Non-polar solutes are more soluble In non-polar solvents.
Ans. (……)
Example
Solution
Mark the statement TanalF
7. I

17. For [CrCl3.xNH3], elevation in boiling point of one molal solution is triple of
one molal aqueous solution of urea. Assuming 100% ionisation of complex
molecule and coordination number as 6, calculate the value of x.
Ans. (……. )
Example
Solution
-
S

18. An aqueous solution of an acid is so weak that it can be assumed to be
practically unionised, boiled at 100.4°C, 25 ml of this solution was
neutralised by 38.5 ml of 1 N solution of NaOH. Calculate basicity of the acid
if kb(H2O) = 0.52 k mol–1 kg.
(Assume molality is equal to molarity)
Ans. (……. )
Example
Solution
②

19. The vapour pressure of two pure liquids A and B that forms an ideal
solution are 300 and 800 torr respectively at temperature T. A mixture of
the vapours of A and B (for which the mole fraction of A is 0.25) is slowly
compressed at temperature T. The vapour pressure of this condensate on
100% condensation of vapour is measured to be 'P'. What is the value of
684 – P?
Ans. (……)
Example
Solution
⑤

20. A compound X undergoes tetramerisation in a given organic solvent.
The van't Hoff factor i is calculated as 0.05y. Find y.
(Assuming 100% association)
Ans. (……)
Example
Solution
⑮

21. If Fe3[Fe(CN)6] gets ionized completely in a solution, number of particles in
the solution from 1 molecule of solute is ________
Ans. (……. )
Example
Solution
④

22. An electrically neutral ionic crystal contains metal ion M+x. metal ion N+y
and oxide ions. Oxide ions form C.C.P. lattice while M+x is present at
𝟏
𝟖
th of
tetrahedral void and N+y is present at
𝟏
𝐀
th of octahedral voids. If 0.1 M of
N(Cl)y solution at 300 K has osmotic pressure 9.6 atm, then (A2 + 4xy) is
Given : i.
𝒚.𝒙
𝑨
is odd number and y, x and A all the positive integers in
which 𝐀 ≤ 𝐲.
ii. R = 0.8
𝐚𝐭𝐦 𝐋
𝐦𝐨𝐥 𝐊
and N(Cl)y is 100% dissociated.
Ans. (……)
Example
Solution
25

23. The osmotic pressure of two aqueous urea solutions-I and II are 2.1 atm
and 1.8 atm respectively at 25°C. The osmotic pressure (in atm) of a
solution at 25° prepared by mixing solution I and II in the volume ratio of
2 : 1 is
Ans. (…….)
Example
Solution
②

24. The boiling point elevation constant for toluene is 3.32 K kg mol–1. The
normal boiling point of toluene is 110.7°C. The enthalpy of vaporisation of
toluene (in kJ/mol) would be nearly.
Ans. (…… )
Example
Solution
21 K] mol-

25. Vapour pressure of aq. Solution of sucrose at 373 K is found to be 750 mm
Hg the molality of solution of same temp.
(a) 0.26 (b) 0.70 (c) 0.74 (d) 0.039
Ans. (…….)
Example
Solution
0.74