Question

Predict the pH ( >7,< 7, or ≈7 ) of aqueous solutions containing the following salts. (a) KBr: >7 <7 ≈7 (b) Al(NO3)3: >7 <7 ≈7 (c) BaCl2: >7 <7 ≈7

Answer 1

Sol :-

(a). pH of solution of KBr is ≈7, because KBr in aqueous solution gives a strong base i.e. KOH and strong acid i.e. HBr, therefore pH of its solution will be ≈7.

For. e.g :-

KBr + H₂O -------------> KOH + HBr

(b). pH of solution of Al(NO₃)₃ is < 7 , because Al(NO₃)₃ in aqueous solution gives a weak base i.e. Al(OH)₃ and a strong acid i.e. HNO₃, therefore pH of its solution will be < 7.

For. e.g :-

Al(NO₃)₃ + 3 H₂O -------------> Al(OH)₃ + 3 HNO₃

(c). pH of solution of BaCl₂ is ≈7 , because BaCl₂ in aqueous solution gives a strong base i.e. Ba(OH)₂ and strong acid i.e. HCl, therefore pH of its solution will be ≈7.

For. e.g :-

BaCl₂ + 2 H₂O -------------> Ba(OH)₂ + 2 HCl