IB Chemistry on Acid Base, pH Scale and Ionic Product Water, Kw

1. Brønsted-Lowry Acid - substance that donate proton/proton donor
Bronsted-Lowry Base – substance that accept proton/proton acceptor
One species donate proton – one species accept proton
Arrhenius acid - substance dissociate in water produce H+ ion.
Arrhenius base – substance dissociate in water produce OH-ion.
All Arrhenius acid are Bronsted Lowry acid and water must be present
HCI → H+ + CI-
HCI + H2O ↔ H3O+ + CI-
NaOH → Na+ + OH-
NH3 + H2O ↔ NH4
+
+ OH-
CO3
2- + H2O ↔ HCO3
- + OH-
Water/aqueous medium
Water/aqueous medium
Other solvent medium possible
Definition of Acid and Bases
Arrhenius acid Arrhenius baseH+ OH-
2
1
gain H+
Acid + Base ↔ Conjugate Base + Conjugate Acid
lose H+
HCI (acid) - CI- (conjugate base)
lose H+
H2O (base) - H3O+ (conjugate acid)
HCI + H2O ↔ CI- + H3O+
gain H+
Lewis Acid - substance that accept electron/electronacceptor, empty orbital/electrondeficient
Lewis Base – substance that donate electron/electrondonor, lone pair electron
Lewis Base - donate electron pair forming dative/coordinatebond with Lewis acid
3
HCI + H2O → CI- + H3O+
H2O donate e-
HCI accept e-
Lewis acid Lewis base
Conjugate acid
base pair differ
by one proton

2. Physicalproperties of Acid
• Substancedissolvesin water produce
hydrogen ion/H+ or hydronium /H3O+
• HCI → H+ + CI-
• Conduct electricity – free movingions
• Sour, pH < 7
• Turn blue litmus red
• Turn phenolphthaleincolourless
• Turns methyl orange to red
Properties of Acids and Bases
Acid+ Metal (above H) → Salt + H2 gas
2HCI + Mg → MgCI2 + H2
Acid + Base → Salt + Water + product.
Bases are - Metal Hydroxide,Metal Oxide, Metal Carbonates
Acid + Metal Hydroxide → Salt + Water
Acid + Metal Oxide → Salt + Water
Acid + Metal Carbonate → Salt + Water + Carbon Dioxide
Acid + Ammoniaaq and Amines → Salt + water
HCI + NH4OH → NH4CI + H2O
HCI + CH3NH2 → CH3NH3 + CI-
Chemical properties of Acids / Bases
Physical properties of Acid
Physical properties of Bases
• Substance dissolvesin water produce
hydroxide/OH- ion
• NaOH → Na+ + OH-
• Conduct electricity– free moving ions
• Bitter, pH > 7
• Turns red litmus blue
• Turns phenolphthalein pink
• Turns methyl orange to yellow
Physical properties of Base
Physical Properties Chemical Properties
Physical Properties
Chemical Properties
Hydronium/Hydroxonium/Oxonium

3. Physicalproperties of Acid
• Electrolytes,produce H3O+,hydronium ion
• Conduct electricity
• Sour, pH < 7
• Turn litmus red
• Turn phenolphthaleincolourless
• Turn methyl orange to red
Physicalproperties of Base
• Bitter,pH > 7
• Turn litmus blue
• Turn phenolphthaleinpink
• Turn methyl orange to yellow
Physical/ChemicalProperties of Acids and Bases
Chemical properties of Acid / BasePhysical properties of Acid/Base
Bases
Acid + Metal Hydroxide (Alkali) → Salt + Water
LiOH + HCI → LiCI + H2O
NaOH + HNO3 → NaNO3 + H2O
KOH + H2SO4 → K2SO4 + H2O
Acid + Metal Hydroxide (Insoluble) → Salt + Water
Ca(OH)2 + 2HCI → CaCI2 + 2H2O
Fe(OH)2 + 2HNO3 → Fe(NO3)2 + 2H2O
Mg(OH)2 + H2SO4 → MgSO4 + 2H2O
Acid + Metal Oxide → Salt + Water
CaO + 2HCI → CaCI2 + H2O
CuO + 2HCI → CuCI2 + H2O
Acid + Alkali
Acids + Metal Oxide
Acid + Metal Hydroxide
Acid + Metal Carbonate
Acid + Metal Carbonate → Salt, Water + CO2
CaCO3 + 2HCI → CaCI2 + H2O + CO2
CuCO3 + 2HCI → CuCI2 + H2O + CO2
Acid+ Metal (above H) → Salt + H2 gas
2HCI + Mg → MgCI2 + H2
Acid + Base → Salt + Water + product.
Bases are - Metal Hydroxide,Metal Oxide, Metal Carbonate
Acid + Metal Hydroxide → Salt + Water
Acid + Metal Oxide → Salt + Water
Acid + Metal Carbonate → Salt + Water + Carbon Dioxide
Acid + Ammoniaaq and Amines → Salt + water
HCI + NH4OH → NH4CI + H2O
HCI + CH3NH2 → CH3NH3 + CI-

4. CH3COOH ↔ H+ + CH3COO-
(1 mole) (0.01 mole)
Strong Acid / Base Weak Acid / Base
Strong acid – ionise/dissociate completelyproducing H+
ion
Strong base – ionise/dissociate completelyproducing OH-
ion
All are in ions state, NO molecule left
Strong electrolytewith high conductivity ↑
Weak acid – ionise/dissociate partially producing H+
ion
Weak base – ionise/dissociate partiallyproducing OH-
ion
Most in undissociated molecule form
Poor electrolytewith low conductivity↓
HCI → H+ + CI-
HBr → H+ + Br−
Monoprotic acid - 1 mole H+
ion
Diprotic acid - 2 mole H+
ion
H2SO4 → 2H+
+ SO4
2-
(1 mole) (2 mole)
Strong Acid - HI, HBr, HCI, HNO3, H2SO4, HCIO3, HCIO4
Strong Base - LiOH, KOH, NaOH, CsOH, Ca(OH)2, Ba(OH)2
Weak Acid - CH3COOH, HF, HCN, H2CO3, H3BO3, HNO2, H3PO4
Weak Base - NH3, C2H5NH2 , CH3NH2, (CH3)2NH, C3H5O2NH2
Weak acid dissociate partially produce few H+ ion
NH3 + H2O ↔ NH4
+ + OH-
C2H5NH2 + H2O ↔ C2H5NH3
+
+ OH-
CO3
2-
+ H2O ↔ HCO3
-
+ OH-
Weak base dissociate partially produce few OH- ion
Vs
Example of Strong Acid/Base Example of Weak Acid/Base
Ba(OH)2 → Ba2+ + 2OH−
(1 mole) (2 mole)
(1 mole) (1 mole)
Dissociatecompletely
No moleculesleft
All ion form Few ions
form
Dissociatepartially
Molecules left
Monoprotic base - Accept 1 mole H+ ions by 1mole OH-
Na(OH) → Na+ + OH−
(1 mole) (1 mole)
All ion form
Dissociatecompletely
No moleculesleft
Few ions
form
Dissociatepartially
Molecules left
H3PO4 ↔ H+ + H2PO4
-
H2PO4
- ↔ H+ + HPO4
2-
HPO4
2-
↔ H+ + PO4
3-
H3PO4 ↔ 3H+
+ PO4
3-
Diprotic base - Accept 2 mole H+ ions by 2 mole OH-
Weak triprotic acid dissociate partially produce few H+ ion
One way reversible
reversible
One way
One way
reversible

5. CH3COOH ↔ H+ + CH3COO-
(1 mole) (0.01 mole)
Strong Acid / Base Weak Acid / Base
Strong acid – ionise/dissociate completelyproducing H+
ion
Strong base – ionise/dissociate completelyproducing OH-
ion
All are in ionic ions state
Strong electrolytewith high conductivity ↑
Weak acid – ionise/dissociate partiallyproducing H+
ion
Weak base – ionise/dissociate partiallyproducing OH-
ion
Most in undissociated molecule form
Poor electrolytewith low conductivity↓
HCI → H+ + CI-
HBr → H+ + Br−
Monoprotic acid - produce 1 mole H+
ions
Diprotic acid - 2 mole H+
H2SO4 → 2H+
+ SO4
2-
Strong acid - HI, HBr, HCI, HNO3, H2SO4, HCIO3, HCIO4
Strong base - LiOH, KOH, NaOH, CsOH, Ca(OH)2, Ba(OH)2
(1 mole) (2 mole)
Weak Acid - CH3COOH, HF, HCN, H2CO3, H3BO3, H3PO4
Weak Base - NH3, C2H5NH2 , (CH3)2NH, C3H5O2NH2
Weak acid dissociate partially produce few H+
ion
NH3 + H2O ↔ NH4
+ + OH-
C2H5NH2 + H2O ↔ C2H5NH3
+
+ OH-
CO3
2-
+ H2O ↔ HCO3
-
+ OH-
Weak bases dissociate partially produce few OH-
ion
Vs
Example Strong Acid/Base Example Weak Acid/Base
Concentrated Acid / Base Diluted Acid / Base
Concentrated Acid – High number of mole/amt of solute per dm3
1 M HCI – 1 mole of HCI moleculesin 1 dm3
10 M HCI – 10 mole of HCI moleculesin 1 dm3
Diluted Acid – Low number of mole/amt of solute per dm3
0.1M HCI – 0.1 mole of HCI molecule in 1 dm3
0.01M HCI – 0.01 mole of HCI molecule in 1 dm3
ConcentratedAcid may NOT be a Strong Acid
10M CH3COOH – Concentrated Acid ↑ but Weak Acid ↓
DilutedAcid may be a Strong Acid
0.01M HCI – DilutedAcid ↓ but Strong Acid ↑
10M CH3COOH - CONCENTRATED WEAK acid because 10M acid molecule will dissociate partially forming few H+
ions
0.01M HCI - DILUTED STRONG acid because all 0.01M acid molecule dissociate fully forming H+
ions
Vs
Diprotic base - 2 mole OH-
Ba(OH)2 → Ba2+ + 2OH−
(1 mole) (2 mole)
(1 mole) (1 mole)

6. Strong/Weak Acid and Base
Strong Acid/Weak Acid
Strong acid - HI, HBr, HCI, HNO3, H2SO4, HCIO3, HCIO4
Weak Acid - CH3COOH, HF, HCN, H2CO3, H3BO3, H3PO4
Strong Base/ Weak Base
Strong base - LiOH, KOH, NaOH, CsOH, Ca(OH)2
Weak Base - NH3, C2H5NH2, (CH3)2NH, C3H5O2NH2
Distinguishbet strong and weak acid
ElectricalconductivityRate of rxn pH
Strongacid
Strong acid → High ionization → High conc H+ → High conductivity→ High rate rxn → Lower pH
Strong acid
Oxoacid
O atom > number ionizable proton
HNO3, H2SO4, HCIO3,HCIO4
Hydrohalicacid
HI, HBr, HCI
Weak acid
Hydrohalicacid
HF
Oxoacid
O atom ≥ number ionizable protonby 1
HCIO, HNO2, H3PO4
Carboxylicacid
COOH
Strong base – containOH- or O2-
LiOH, NaOH, CaO, K2O Ca(OH)2, Ba(OH)2
Weak base – contain electronrich nitrogen, N
NH3, C2H5NH2, (CH3)2NH, C3H5O2NH2
Strong base Weak base
1 2 3
Weak acid
0.1 M HCI 0.1 M CH3COOH
H+ 0.1 mole 0.0013 mole
pH 1 (Low) 2.87 (High)
Electrical conductivity High (Ionize completely) Low (Ionize partially)
Rate with magnesium Fast Slow
Rate with calcium
carbonate
Fast Slow
Weaker acid → Low ionization → Low conc H+ → Low conductivity→ Low rate rxn → High pH
Strong acid
HA A-H+
H+ H+
H+
H+ H+
H+
H+A-
A-
A-
A- A-
A-
Ionizes completely
Weak acid
HA
HA
H+ A-
H+
H+
A-
A-
HA
HA
HA
HA
HA
HA
Ionizes partially

7. Easier using pH scale than Conc [H+]
• Conc H+ increase 10x from 0.0001(10-4) to 0.001(10-3)
- pH change by 1 unit from pH 4 to 3
• pH 3 is (10x) more acidic than pH 4
• 1 unit change in pH is 10 fold change in Conc [H+]
Conc OH-
increase ↑ by 10x
pH increase ↑ by 1 unit
pOH with Conc OH-
pOH = -log [OH-
]
[OH-
] = 0.0000001M
pOH = -log [0.0000001]
pOH = -log1010-7
pOH = 7
pH + pOH = 14
pH + 7 = 14
pH = 7 (Neutral)
pH with Conc H+
pH = -log [H+
]
[H+
] = 0.0000001M
pH = -log [0.0000001]
pH = -log1010-7
pH = 7 (Neutral)
Conc H+
increase ↑ by 10x
pH decrease ↓ by 1 unit
pH measurement of Acidity of solution
• pH is the measureof acidity of solutionin logarithmicscale
• pH = powerof hydrogenor minuslogarithmto base ten of hydrogenion concentration
← Acidic – pH < 7 Alkaline – pH > 7 →
pOH with Conc OH-
pOH = -log [OH-
]
[OH-
] = 0.1M
pOH = -log[0.1]
pOH = 1
pH + pOH = 14
pH + 1 = 14
pH = 13 (Alkaline)
pH with Conc H+
pH = -log [H+
]
[H+
] = 0.01M
pH = -log [0.01]
pH = -log1010-2
pH = 2 (Acidic)
Easier pH scaleConc H+

8. Conc [H+
] = 1 x 10-12
pH = -lg[H+
]
pH = -lg[10-12
]
pH = 12
Conc [OH-
]= 1 x 10-2
pOH = -log10[OH-]
pOH = -log1010-2
= pOH = 2
pH + pOH = 14
pH + 2 = 14
pH = 12
Conc [H+
] = 1 x 10-2
pH = -lg[H+
]
pH = -lg[10-2
]
pH = 2
Alkaline
Alkaline
Acidic
Acidic
Kw - Ionic product constant water
Using conc [H+]
pH = -log10[H+]
pH = -log10[H+] pOH = -log10[OH-] pH + pOH = 14 Kw = [H+][OH-]
Using conc [OH-]
pOH = -log10[OH-]
Conc[OH-
]= 1 x 10-12
pOH = -log10[OH-]
pOH= -log1010-12
=pOH = 12
pH + pOH = 14
pH + 12 = 14
pH = 2
Formula for acid/basecalculation
  
 22
3
OH
OHOH
Kc


    
 OHOHOHKc 3
2
2
  
 OHOHKw 3
  
 OHOH3
14
100.1
  7714
101101100.1 

  7
101 
OH
  
 OHOHOHOH 322
H2O dissociateforming H3O+ and OH-
(equilibriumexist)
14
100.1 
wK
Dissociation water small [H2O] is constant
Kw = 1.0 x 10-14 Ionic Product constantwater at -25C
Kc - Dissociation constant water
  7
3 101 
OH

9.  
 
0.2
01.0log
log
10
10


 
pH
pH
HpH
  
 22
3
OH
OHOH
Kc


    
 OHOHKOHK wc 3
2
2
  
 OHOH3
14
100.1   7714
101101100.1 


 OHOHOHOH 322
H2O dissociateforming H3O+ and OH-
(equilibriumexist)
14
100.1 
wK
Dissociation water small [H2O] is constant
Kw - Ionic product constant water
Kw = 1.0 x 10-14 Ionic Product constant water at -25C
Kc - Dissociation constant water
Cal conc of H+ ,OH- and pH of water Cal conc of H+ ,OH- and pH of 0.01M HCI

 OHHOH2
  
 OHHKw
  
 OHH14
100.1
  7714
101101100.1 

  7
101 
H
H2O H2O
HCI

 OHHOH2
H2O
  
 OHHKw
  
 OHH14
100.1
Assuming H+ all from HCI = 0.01
)()( 2OHHHCIHH 

H+ = 0.01 + 1.0x10-12
= 0.01 + 0.000000000001
≈ 0.01

 OHHOH2
H+ = 1x10-12 OH- = 1x10-12

 CIHHCI
0.01 mol 0.01 mol0.01
1 mol ↔ 1 mol 1mol
0.000000000001
0.000000000001
H+
OH-
= 0.01 = 0.000000000001
or
 
0.7
101log 7
10

 
pH
pH
  
 
0.21214
12
100.1
01.0
100.1
01.0100.1
12
14
14










pH
pOH
OH
OH

10.   
 22
3
OH
OHOH
Kc


    
 OHOHKOHK wc 3
2
2
  
 OHOH3
14
100.1   7714
101101100.1 


 OHOHOHOH 322
H2O dissociate forming H3O+ and OH-
(equilibrium exist)
14
100.1 
wK
Dissociation water small [H2O] is constant
Kw - Ionic product constant water
Kw = 1.0 x 10-14 Ionic Product constant water at -25C
Kc - Dissociation constant water
Cal conc of H+ ,OH- and pH of 0.01M KOH Cal conc of H+ ,OH- and pH of 0.1M H2SO4
 
 
7.0
2.0log
log
10
10


 
pH
pH
HpH
H2O
KOH
H2SO4

 OHHOH2
H2O
  
 OHHKw
  
 OHH14
100.1
Assuming H+ all from H2SO4 = 0.2
  
 
7.03.1314
3.13
100.5
2.0
100.1
2.0100.1
14
14
14










pH
pOH
OH
OH
)()( 242 OHHSOHHH 

H+ = 0.2 + 5 x 10-14
= 0.2 + 0.000000000000005
≈ 0.2

 OHHOH2
H+ = 5x10-14 OH- = 5x10-14


2
442 2 SOHSOH
0.1 mol 0.2 mol
0.2
1 mol ↔ 1 mol 1 mol
0.00000000000005
0.0000000000005
H+
OH-
= 0.2 = 0.00000000000005

 OHHOH2
1 mol ↔ 1 mol 1 mol

 OHHOH2
  
 OHHKw

 OHKKOH
0.01 mol 0.01 mol
0.01
Assuming OH- all from KOH = 0.01
)()( 2OHOHKOHOHOH 

= 0.01 = 0.000000000001
  
 
 
 
12
10log
log
101
01.0
100.1
01.0100.1
12
10
10
12
14
14













pH
pH
HpH
H
H
or
H+ = 1x10-12 OH- = 1x10-12

11. Number sig fig in log calculation
Significant number in log calculation
log10(3575)=3.55327 = 3.5532
log10(3.000x104) = 4.477121 = 4.4771
log10(3.3 x 104) = 4.5185 = 4.51
Calculation involve pH = -log10[H+]
Conc H+ = 1.9 x 10-4
pH= -log10[1.9 x 10-4] = 3.721 = 3.72
Measurement scale not linear
• Simple average CANNOT be used
• Average of pH 7, pH 8, pH 9
pH scale is logarithmic, pH = -log[H+]
Correct average = convert to H+ conc
pH 7 = -log10[H+] → H+ = 10-7
pH 8 = -log10[H+] → H+ = 10-8
pH 9 = -log10[H+] → H+ = 10-9
pH pH= -lg10H+ Conc H+
0 0 = -lg10100 1.0
1 1 = -lg1010-1 0.1
2 2 = -lg1010-2 0.01
3 3 = -lg1010-3 0.001
4 4 = -lg1010-4 0.0001
5 5 = -lg1010-5 0.00001
6 6 = -lg1010-6 0.000001
7 7 = -lg1010-7 0.0000001
8 8 = -lg1010-8 0.00000001
9 9 = -lg1010-9 0.000000001
10 10= -lg1010-10 0.0000000001
11 11= -lg1010-11 0.00000000001
12 12= -lg1010-12 0.000000000001
13 13= -lg1010-13 0.0000000000001
14 14= -lg1010-14 0.00000000000001
Easier using pH scale than Conc [H+]
• Low pH – High H+ conc – More acidic
• High pH – Low H+ conc – Less acidic
• pH 3 (10x) more acidic > than pH 4
• 1 unit change in pH is 10 fold change in Conc [H+]
Relationship between pH and Conc H+
Uncertainty involving pH
8
3
987


Average
Uncertainty involving pH
4 sig fig 5 sig fig/4 decimal place
4 sig fig 5 sig fig/4 decimal place
Conc H+ = 3.2 x 10-5 M
pH = - log10[3.2 x 10-5]= 4.4948 = 4.49
2 sig fig 3 sig fig/2 decimal place
2 sig fig3sig fig/2 decimal place
2 sig fig3sig fig/2 decimal place
2 sig fig 3sig fig
2 sig fig3 sig fig
2 sig fig 3 sig fig
pH solution = 7.40. Cal conc of H+ ions
7.40 = -log10 [H+]
[H+] = 10-7.40
= 4.0 x 10-8
3 sig fig 2 sig fig
2 sig fig
4.7
]107.3lg[
107.3
3
101010
8
8
987








pH
pH
Average
Average

12. What is pH for [H+
] = 1 x 10-12
M
pH = -lg [10-12
]
pH = 12
What is conc of H+
of pH 3.20?
3.20 = -lg [H+
]
[H+
] = 10 –2.20
[H+
] = 6.3 x 10-4
pH = -log10[H+] pOH = -log10[OH-] pH + pOH = 14 Kw = [H+][OH-]
Formula acid/basecalculation
2 sig fig 1 sig fig 3 sig fig 2 sig fig
What is pH for [OH-
] = 0.15M
pOH = -lg [0.15]
pOH = 0.823
pH + pOH = 14
pH = 14 – 0.823 = 13.2
pOH = -log[OH-]
3 sig fig 2 sig fig
Calculate conc of H+, OH-
and pH for 0.0010M HCI.
1 2 3
4

 CIHHCI
0.001 ↔ 0.001 0.001

 OHHOH2
HCIH2O
  
 OHHKw
Assuming H+ all from HCI = 0.0010
)()( 2OHHHCIHH 

= 0.001 Negligible / too little
  
 OHH14
100.1
 
 
0.3
001.0log
log
10
10


 
pH
pH
HpH
  
 
0.31114
11
101
001.0
100.1
001.0100.1
11
14
14










pH
pOH
OH
OH
or
Cal conc OH-
/pH when3.o x 10-4
H+
add water
HCI
H2O

 CIHHCI
 OHHOH2
  
 OHHKw
  
 OHH14
100.1
  
  11
4
14
414
103.3
100.3
100.1
100.3100.1










OH
OH
3x10-4 ↔ 3x10-4
 
 
52.3
100.3log
log
4
10
10





pH
pH
HpH

13. pH weak acid at variousconcentration

 HCOOCHOHCOOHCH 2323
Extendof dissociationdependon initialconcentrationacid
Conc of acid Observed pH CH3COOH CalculatedpH HCI
0.10 2.7 1.0
0.010 3.0 2.0
0.0010 3.5 3.0
0.00010 4.2 4.0

 CIHHCI
Weak acid Strong acid
Dissociate partially Dissociate completely
At same acid concentration
• HCI has HIGHER[H+] > CH3COOH
• HCI has LOWER pH < CH3COOH
• HCI dissociate completely - Strong acid
• CH3COOH dissociatepartially - Weak acid
At decreasing acid concentration
• Extend of dissociation for CH3COOH increase
• pH weak acid closer to strong acid
• Dilution increase the extend of dissociation
Conc decrease

 HCOOCHOHCOOHCH 2323
Trends
Addition Water
Dilution shift equilibrium to right
Decreaseconc of CH3COOH,CH3COO- andH+
Conc on left side is more effecteddue to CH3COO- and H+
Equilibrium shift to right to increase
conc of CH3COO- and H+ again
Extend of dissociation for acid increase (shift to right)
О
О
Concept Map
[H+] [OH-]
pH pOH
Kw = [H+] x [OH-] = 1 x 10-14
pH + pOH = 14
pH = -lg [H+] [H+] = 10-pH pOH = -lg [OH-] [OH-] = 10-pOH

14. Question on Acid and Base
Which list contains only strong acids ?
A. CH3COOH, H2CO3, H3PO4
B. HCI, HNO3, H2CO3
C. CH3COOH, HNO3, H2SO4
D. HCI, HNO3, H2SO4
When equal volume of four 1M solutions are arranged in order of increasing pH (lowest pH first), what is the correct order?
A. CH3COOH < HNO3 < CH3CH2NH2 < KOH
B. HNO3 < CH3COOH < CH3CH2NH2 < KOH
C. CH3CH2NH2 < HNO3 < CH3COOH < KOH
D. KOH < CH3CH2NH2 < CH3COOH < HNO3
pH of a solution changes from pH =2 to pH =5. What happens to the concentrationof H+ ions during this pH change?
A. Decrease by factor of 1000
B. Increase by factor of 1000
C. Decrease by factor of 100
D. Increase by a factor of 100
Solution of acid A has a pH of 1 and a solution of acid B has a pH of 2. Which statement is correct ?
A. AcidA is stronger than acid B
B. [A] > [B]
C. Concentrationof H+ ions in A is higher than B
D. Concentrationof H+ ions in B is twice the concentrationof H+ in A
100ml of NaOH solution of pH 12 is mixed with 900ml of water. What is the pH of resulting solution?
A. 1
B. 3
C. 11
D. 13
1
2
3
4
5
О
О
О
О
О
List two ways to distinguish between strong and weak acid/base6
By Conductivitymeasurement
1M StrongAcid – Ionise completely– More H+ ion – pH lower ↓
1M Weak Acid – Ionise partially – Less H+ ion – pH higher ↑
1M StrongAcid – Ionise completely– More H+ ion – Conductivityhigher ↑
1M Weak Acid – Ionise partially – Less H+ ion – Conductivitylower ↓
By pH measurement
Which methodwill distinguishbet equimolarstrong base and strong acid?
i) Add magnesiumto each solutionand observeformationbubbles
ii) Add aqueoussodium hydroxideto each solutionand measuretemp change
iii) Use each solutionin circuit with battery/lampto see brightnesslamp
7
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15. Click here on pH calculation Click here on Bronsted Lowry/ Lewis Acid/Base
Video on Acid/ Base
Click here on Lewis Acid/Base
Click here on pH varies with temperature Click here on pKa and pKb calculation