If `0.5g` of a mixture of two metals A and B with respective equivalent weights 12 and 9 displace 560ml of `H_2` at STP from an acid, the composition of the mixture is

Options

A. `40% A, 60% `
B. `60%A, 40% B`
C. ` 30%A, 70%B`
D. `70% A, 30%B `

Answer

A

Explanation

1 mol of `H _(2) = 22400 mL = 2 ` Eq of `H _(2) , 1 Eq of H _(2) = 11200 mL.`
Eq of `H _(2) = ( 560)/(11200 ) = (1)/(20) Eq,`[Let the weight of A be x g, weight of `B = 0. 5 - x`]
Eq of A + Eq of `B = Eq of H _(2) , ( x)/(12) + (0.5- x )/( 9) = (1)/(20) therefore x = 0.2`
`% of A = ( 0.2 xx 100)/(0.5) = 40% , % of B = 60%`