The given question and options are given below:
1.0 g of the carbonate of a metal was dissolved in 25 mL of 1.0 N HCl. The resulting liquid required 5 mL of 1.0 N NaOH for neutralization. The equivalent weight of the metal carbonate is: [2.5 M]
(A) 50
(B) 30
C) 20
(D) None of these
The correct answer is (C) 20.
Explanation:
Equivalent weight of metal carbonate = (Weight of metal carbonate / Equivalents of metal carbonate)
Equivalents of metal carbonate = Equivalents of HCl used - Equivalents of NaOH used
Equivalents of HCl used = (25 mL * 1.0 N) = 25 meq
Equivalents of NaOH used = (5 mL * 1.0 N) = 5 meq
Therefore, Equivalents of metal carbonate = 25 meq - 5 meq = 20 meq
Weight of metal carbonate = 1.0 g
Therefore, Equivalent weight of metal carbonate = (1.0 g / 20 meq) = 20
Hence, the equivalent weight of the metal carbonate is 20.