Question

How many grams of chlorine can be produced by the electrolysis of molten NaCl with a current of 1.0A for 15 min ?

Answer 1

`2NaCl(l)rarr2Na^(+)(l)+2Cl^(-)(l)`
`2Cl^(-)(l)rarrCl_(2)(g)+underset((2 " mol"))(2e^(-))`
The charge Q on n mol of electrons is given by,Q=nF Thus, `Q=2 "mol"xx96500 " C mol"^(-1)=193000 C=1.93xx10^(5) C`
Quantity of electricity used `="Current in amperes"xx"Time in seconds"`
`=(1.0 A)xx(15xx60)s`
`1.0xx15xx60 A.s=900 C " "(`:.`A.s=C)`
Molar mass of chlorine `(Cl_(2))= 2xx35.5 " g mol"^(-1)=71 " g mol"^(-1)`
`1.93xx10^(5) C` of charge produce chlorine =1 mol=71 g
Therefore,900 C of charge produce produce chlorine` =((71g))/((1.93xx10^5 C))xx(900 C)=0.331 g`.