Question

$0.833$ mole of a carbohydrate, with empirical formula $C{H}_{2}O$ , has $10g$ of hydrogen. Molecular formula of carbohydrate is :

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

Answer 1

Answer: (B)

Given: moles of carbohydrate $=0.833$
Hydrogen $=10g$
$\because 0.833$ moles of carbohydrate has hydrogen $=10g$
$\therefore 1$ mole of carbohydrate has hydrogen $=\frac{10}{0.833}\times 1=12g$
Given: empirical formula of carbohydrate $=C{H}_{2}O$
$\because$ $C{H}_{2}O$ contains hydrogen $=2g$ hydrogen per mole Molecular formula should contain hydrogen $=\frac{12}{2}\times 2=12$
$\therefore$ Molecular formula of hydro carbon $=C_6{H}_{12}{O}_6$