Question

The ratio of the mass percentages of 'C and H' and C &O of a saturated acyclic organic compound 'X' are 4:1 and 3:4 respectively. Then, the moles of oxygen gas required for complete combustion of two moles of organic compound 'X' is

Answer 1

$C:H=4:1$
$C:O=3:4$
Mass ratio
$C:H:O12:3:16$

Mole ratio:
$C:H:O\frac{12}{12}:\frac{3}{1}:\frac{16}{16}1:3:1$
Empirical formula $=C{H}_{3}O$
Molecular formula $=C_2{H}_6{O}_2$
(saturated acyclic organic compound)
General reaction:
$C_x{H}_y{O}_z+(x+\frac{y}{4}-\frac{z}{2})O_2\to xC{O}_2+\frac{y}{2}{H}_{2}O$
$C_2{H}_6{O}_2+\frac{5}{2}{O}_2\to 2C{O}_2+3H_{2}O$
1 mol of organic compound reacts with 2.5 mol of oxygen
So,
2 moles of organic compound reacts with 5 moles of oxygen.