One mole of chlroine combines with certain weight of a metal giving 111 g of its chloride. The same amount of metal can displace 2 g of hydrogen from an acid. The atomic weight of the metal is

Weight of Chlorine = 71gWeight of metalchloride = 111gWeight of metal = 40g40g metal displaces 2 grams of H2   EM = 20 40g metal displaces 2 g equivalent of H2 then valency of the metal is 2 AW = EW 2AW = 20 2 = 40