0.01 mole of an organic compound (X) containing 10% hydrogen, on complete combustion produced $$0.9_{g}H_{2}O$$. Molar mass of (X) is_____$$mol^{-1}$$.

0.01 mole of compound X containing 10% hydrogen produces 0.9 g H₂O on combustion. Find molar mass.

Find mass of hydrogen in the water produced

Mass of H in H₂O = $$\frac{2}{18} \times 0.9 = 0.1$$ g

Find mass of compound X

Since X contains 10% hydrogen:

Mass of H = 10% of mass of X

$$0.1 = 0.10 \times m_X$$

$$m_X = 1$$ g

Find molar mass

0.01 mol of X has mass 1 g:

$$M = \frac{1}{0.01} = 100$$ g/mol

The answer is 100.