An organic compound gives 0 . 220g of CO _ 2 and 0 . 126g of H _ 2...

Moles of ${CO}_{2} = \dfrac{0 . 22}{44} = \dfrac{1}{200}$

Then,

Mass of $C = \dfrac{0 . 220}{44} \times 12 = 0 . 06g$

$$

(W= Wt.of organic compound)

$W = 0 . 25$

Moles of ${H}_{2}O = \dfrac{0 . 126}{18} = 0 . 007$

Moles of $H = 0 . 007 \times 2 = 0 . 014g$

$$

$= 56 \times {10}^{- 1}$