Question

A metal oxide has the formula Z₂O₃ . It can be reduced by hydrogen to give free metal and water . 0.16 gm of the metal oxide requires 6 mg of hydrogen for complete reduction. The atomic weight of a metal is:

Answer 1

Given,
Metal oxide has the formula Z₂O₃
Valency of the metal in Z₂O₃ = 3
Z₂O₃ + 3H₂ → 2Z + 3H₂O
As 0.16 g of Z₂O₃ reacts with H₂ = 6 mg = 0.006 g
So, 1 g of H₂ react with 0.16/0.006 = 26.67 g of Z₂O₃
Hence,
Equivalent weight of Z₂O₃ = 26.67

Equivalent weight of Z + Equivalent weight of O = E + 8 = 26.67

Therefore,
Equivalent weight of Z = 26.67 - 8 = 18.67

Hence,
Atomic weight of Z = 18.67 x 3 = 56.01