Three Faraday of electricity is passed through aqueous solutions of A g N O 3 , N i S O 4 and C r C l 3 kept in three vessels using inert electrodes. The ratio in mol in which the metals Ag, Ni and Cr will be deposited is

Step-by-step solution

(i) A g + a q 1 mol = 1F 3 F + e - → A g s 1 mol 3 mol (ii) Ni 2 + a q 1 mol = 2F 3 F + 2 e - → N i s 1 mol 3 2 mol (iii) Cr 3 + aq 1  mol = 3F + 3 e − → Cr s 1  mol The required ratio of moles of Ag, Ni and Cr is 3 mol Ag: 3/2 mol Ni : 1 mol Cr or 6 mol Ag : 3 mol Ni : 2 mol Cr.