Question
88.Salts of A ( atomic mass 7 ), B ( atomic mass 27) and C (atomic mass 64) 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. The valencies of A, B and C are respectively : (a) 3, 1 and 2 (b) 1, 3 and 2 (c) 3, 1 and 3 (d) 2, 3 and 2.