From Faraday's Law, mass deposited during electrolysis is given by
\(M_1 = I_1t_1Z\)
=> Z = \(\frac{M_1}{(I_1t_1)}\)

⇒ Z =\(\frac{2}{0.5 \times3}\) = 1.333Kg/C
For a current of 1.5A flowing for 1h, the mass M, deposited is given by
\(M_2 = ZI_2T_2\) = 1.333 x 1 x 1.5 = 2.0g
 \(M_2\) = 2.0g

note: converting time to seconds here is not necessary.