Question

$0.1$ mole of a carbohydrate with empirical formula $C{H}_{2}O$ contains $1g$ of hydrogen. What is its molecular formula ?

• A. $C_5{H}_{10}{O}_5$
• B. $C_6{H}_{12}{O}_6$
• C. $C_4{H}_8{O}_4$
• D. $C_3{H}_6{O}_3$

Answer 1

Answer: (A)

$0.1$ mol of carbohydrate with empirical formula $C{H}_{2}O$ contains $1g$ of hydrogen
$\therefore$ $1$ mol of carbohydrate with empirical formula $C{H}_{2}O$ contains $10g$ of hydrogen $=10g$ atoms
In $C{H}_{2}O$ atomic ratio of $C:H:O=1:2:1$ with $10g$ atoms of $H,g$ atoms of carbon $=5$ and $g$ atoms of oxygen $=5$
$\therefore$ The molecular formula of the carbohydrate is $C_5{H}_{10}{O}_5$