Three faradays of electricity are passed through molten $Al_2O_3$,aqueous solution of $CuSO_4$ and molten $NaCl$ taken in different electrolytic cells. The amount of $Al$,$Cu$ and $Na$ deposited at the cathodes will be in the ratio of

How many coulombs are required to oxidise $0.1 \ mole$ of $H_2O$ to oxygen?

Aluminum oxide is electrolyzed at $1000^\circ C$ to produce aluminum metal. The cathode reaction is $Al^{3+} + 3e^- \rightarrow Al$. What quantity of electricity is required to produce $5.12 \ kg$ of aluminum metal? (Given: $1 \ Faraday = 96500 \ C$)

$Assertion (A)$: $A$ current of $96.5 \ A$ is passed into aqueous $AgNO_3$ solution for $100 \ s$. The weight of silver deposited is $10.8 \ g$ (At. wt. of $Ag = 108$).
$Reason (R)$: The mass of a substance deposited during the electrolysis of an electrolyte is inversely proportional to the quantity of electricity passing through the electrolyte.
The correct answer is :

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 $60 \ s$?

$A$ current of $15.0 \ A$ is passed through a solution of $CrCl_2$ for $45 \ min$. The volume of $Cl_2$ (in $L$) obtained at the anode at $1 \ atm$ and $273 \ K$ is around ($1 \ F = 96500 \ C \ mol^{-1}$,At. wt. of $Cl=35.5$,$R=0.082 \ L \ atm \ K^{-1} \ mol^{-1}$) (in $.7$)