Question

An organic compound contains carbon , hydrogen and oxygen. Its elemental analysis gave $C$ = $38.71$% and $H$ = $9.67$%. The empirical formula of the compound would be

• A. $CHO$
• B. $C{H}_{4}O$
• C. $C{H}_{3}O$
• D. $C{H}_{2}O$

Answer 1

The correct option is C $C{H}_{3}O$

Element	%	Atomic mass	Mole Ratio	Simple Ratio
$C$	$38.71$	$12$	$\left(38.71/12\right)=3.22$	$\left(3.22/3.22\right)=1$
$H$	$9.67$	$1$	$\left(9.67/1\right)=9.67$	$\left(9.67/3.22\right)=3$
$O$	$51.62$	$16$	$\left(51.62/16\right)=3.22$	$\left(3.22/3.22\right)=1$

Simple ratio of $C:H:O=1:3:1$
So empirical formula = $C{H}_{3}O$