$0.066 \ g$ 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?

How many amperes must be passed through a Down's cell to produce sodium metal at a rate of $30.0 \ kg/h$?

If $0.5 \, A$ current is passed through an acidified silver nitrate solution for $10 \, min$,the mass of silver deposited on the cathode is ........... $g$ (equivalent weight of silver $= 108$).

How many atoms of calcium will be deposited at the cathode when a current of $25 \ mA$ is passed through a $CaCl_2$ solution for $60 \ s$?

The ratio of weights of hydrogen gas liberated and magnesium deposited by passing the same amount of electricity from aqueous $H_2SO_4$ and fused $MgSO_4$ are :

$Al_2O_3$ is reduced by electrolysis at low potential and high current. If a current of $4 \times 10^4 \ A$ is passed through molten $Al_2O_3$ for $6 \ h$,how many grams of $Al$ will be produced? (Assume $100\%$ current efficiency and atomic mass of $Al = 27 \ g \ mol^{-1}$)