Question

The empirical formula of a compound is $C{H}_{2}O$. If 0.0833 moles of the compound contains 1 g of hydrogen, find the molecular formula of the compound.

• 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

The correct option is B $C_6{H}_{12}{O}_6$


Empirical formula = $C{H}_{2}O$
0.0833 moles of a compound contains 1 g of hydrogen atom
So, 1 mol of the compound will contain $\frac{1}{0.0833}$ g $\approx 12$ g of hydrogen atom

Molecular formula = n $\times$ empirical formula
where n is the simple whole number
Mass of hydrogen in molecular formula = 12 g
Mass of hydrogen in empirical formula = 2 g
$\therefore$ n = 6
MOlecular formula = $(C{H}_{2}O{)}_6$ = $C_6{H}_{12}{O}_6$