An electroplating tank containing a zinc sulfate solution is used to deposit a 5 μm thick layer of zinc on a metallic component with a surface area of 0.1 m2. If the process takes 20 minutes, what is the constant current required? (Take the density of zinc as 7140 kg/m3 and the electrochemical equivalent of zinc as 0.338 mg/C)

The resistance of a 0.01 M electrolyte solution is 210 Ω at 25°C. If the cell constant is 0.90 cm−1, the molar conductivity of the solution (in S m2 mol−1) is:

Molar conductivity of a weak acid HQ of concentration 0.18 M was found to be 130 of the molar conductivity of another weak acid HZ with concentration 0.02 M. If λ0(Q-) happens to be equal to λ0(Z-), then the difference of the pKa values of the two weak acids (pKa(HQ) - pKa(HZ)) is equal to: