1 mol of a gaseous aliphatic compound `C_nH_(3n)O_m` is completely burnt in an excess of oxygen. The contraction in volume in (assume water gets condensed out ):

Options

A. `(1+(1)/(2)n-(3)/(4)m)`
B. `(1+(3)/(4)n-(1)/(4)m)`
C. `(1+(1)/(2)n-(3)/(4)m)`
D. `(1+(3)/(4)n-(1)/(2)m)`

Answer

4

Explanation

`C_(n)H_(3n)O_(m)+yO_(2)rarrnCo_(2(g))+(3n)/(2)H_(2)O(l)`
Contraction in volume `=` Contration in moles of gas `=1+(3n)/(4)-(m)/(3)=1+(3n)/(4)-(m)/(2)`
`rArr " "(2n+(3n)/(2)-m)xx(1)/(2)=y" "rArr" "n+(3n)/(4)-(m)/(2)=y`