Question

An organic substance containing carbon, hydrogen and oxygen gave the following percentage composition. $C=40.687$ What is the empirical formula of the compound?

• A. $C{H}_{3}O$
• B. $C_2{H}_{2}O$
• C. $C{H}_{4}O$
• D. $C_2{H}_3{O}_2$

Answer 1

Answer: (D)

Symbol
Percentage
Relative no. of moles
Simplest molar ration
Simplest whole no. molar ratio
$C$
$40.687$
$\frac{40.687}{12}=3.390$
$\frac{3.390}{3.389}=1$
2
$H$
$5.085$
$\frac{5.085}{1}=5.085$
$\frac{5.085}{3.389}=1.5$
3
$O$
$54.228$
$\frac{54.228}{16}=3.389$
$\frac{3.389}{3.389}=1$
2
Hence, the epitomical formula of the compound is $C_2{H}_3{O}_2$ .