Salts of A, B and C were electrolysed under identical conditions using the same quantity of electricity. It was found that when 2.1 ~g of A was deposited, the weights of B and C deposited were 2.7 ~g and 9.6 ~g . If the atomic mass of A, B and C respectively are 7,27 and 64 respectively, then the valancies of A, B and C respectively are

Step-by-step solution

Using concept of Faraday law, Now, A^ n₁⁺ +n₁ e⁻ A Similarly, B^ n₂⁺ +n₂ e⁻ B and, C ^ n₃⁺ +n₃ e⁻ C Since, charge is same then equivalent weight is same, array ll & 2.1 7 n₁ = 2.7 27 n₂ = 7.2 48 n₃ & 3 n₁ 10 = 1 n₂ 10 = 3 n₃ 2 10 n₁= n₂ 3 = n₃ 2 & n₁=1, n₂=3 and n₃=2 array Hence, valencies of A, B and C are 1,3 and 2 .