Question

2.5 g of the carbonate of a metal was treated with 100 mL of IN H₂SO₄. After the completion of the reaction, the solution was boiled off to expel CO₂ and was then titrated against IN NaOH solution. The volume of alkali that would be consumed, if the equivalent weight of the metal is 20, is

(a) 50 mL

(b) 25 mL

(c) 75 mL

(d) 100 mL

Answer 1

Correct option  (a) 50 mL

Explanation:

Equivalent weight of metal carbonate= 20+30=50

2.5 g of metal carbonate = 2.5/50 = 0.05 eq.

Number of equivalents of H₂SO₄ that would have reacted = 0.05

Number of equivalents of H₂SO₄ taken 

= 100 x1/1000 = 0.1

Number of equivalents of H₂SO₄ remains unreacted 

= 0.1 - 0.05 = 0.05 eq.

∴ Number of equivalent of alkali consumed = 0.05 eq.