Page 249, n^o 36

1. Basique.
2. Acide.
3. Neutre.
4. Basique.

Page 250, n^o 40

1. pH = 12,54
2. pH = 3,90
3. pH = 7,00
4. pH = 14,70

Page 250, n^o 44

pH = 8,26

[H⁺] = 5,5 × 10^-9 mol/l

[OH^-] = 1,8 × 10^-6 mol/l.

Page 250, n^o 48

1. [H⁺] = [NO₃^-] = 2,0 × 10^-2 mol/l.
   pH = 1,70
2. pH = -0,60
3. pH = 7,00 la concentration de HNO₃ étant très faible.

Page 250, n^o 52

[H+] = 5,6 × 10^-5 mol/l.

Donc il faut une solution de HNO₃ 5,6 × 10^-5 mol/l.

Page 251, n^o 70

[H⁺] = [F^-] = 0,0081 mol/l.

[HF] = 0,0919 mol/l.

K_a = 7,1 × 10^-4

Page 251, n^o 72

[H⁺] = [CCl₃COO^-] = 4,0 × 10^-2 mol/l.

[CCl₃COOH] = 0,010 mol/l.

K_a = 0,16

Page 251, n^o 82

1. [OH^-] = 8,0 × 10^-4 mol/l.
   pOH = 3,10
   pH = 10,90
2. [OH^-] = 2,0 mol/l.
   pOH = -0,30
   pH = 14,30
3. [OH^-] = 1,0 × 10^-7 mol/l.
   pOH = pH = 7,00

Page 252, n^o 86

[OH^-] = 0,10 mol/l.

[Ca(OH)₂] = 0,050 mol/l.

Page 252, n^o 90

1. [OH^-] = 8,7 × 10^-6 mol/l.
   pH = 8,96
2. [OH^-] = 1,8 × 10^-5 mol/l.
   pH = 9,25