$0.066 \ g$ of metal was deposited when a current of $2 \ A$ is passed through a metal ion solution for $100 \ s$. What is the electrochemical equivalent (in $g \ C^{-1}$) of the metal?

Which of the following aqueous solutions will result in the maximum number of moles of metal deposited on passing the same amount of charge?

$A$ metal surface of $100 \, cm^2$ area has to be coated with a nickel layer of thickness $0.001 \, mm$. $A$ current of $2 \, A$ was passed through a solution of $Ni(NO_3)_2$ for '$x$' seconds to coat the desired layer. The value of $x$ is $.........$. (Nearest integer)
($\rho_{Ni}$ (density of Nickel) is $10 \, g \cdot cm^{-3}$,Molar mass of Nickel is $60 \, g \cdot mol^{-1}$,$F = 96500 \, C \cdot mol^{-1}$)

The chemical equivalents of copper and silver are $32$ and $108$ respectively. When copper and silver voltameters are connected in series and electric current is passed through for some time,$1.6 \ g$ of copper is deposited. Then,the mass of silver deposited will be .......... $g$.

When $3 \ F$ of electricity is passed through an aqueous solution of iron $(II)$ bromide,what is the mass of iron metal deposited at the cathode in $g$?

Charge required to liberate $11.5 \ g$ of sodium is: