Question

`4.5 g` of aluminium (at mass `27 u`) is deposited at cathode from `Al^(3+)` solution by a certain quantity of electric charge. The volume of hydrogen gas produced at `STP` from `H^(+)` ions in solution by the same quantity of electric charge will be:
A. 44.8L
B. 11.2L
C. 22.4L
D. 5. 6L

Answer 1

Correct Answer - D
`Al^(3+)+3e^(-)rarrAl`
27g of Al are deposited by a charge =3F
4.5g of Al are deposited by a charge.
`=(3)/(27)x x4.5F=0.5F`
`2H^(+)+2e^(-)rarrH_(2)`.
2F produce `H_(2)=22.4L` at STP
`therefore 0.5F` will produce `H_(2)=(22.4)/(2)xx0.5`
=5.6L