Question

1. what is the percent by mass of carbon in ( c_{10}h_{14}o )? (( c_{10}h_{14}o = 150.2 g/mol ))

a. 30.16 %
b. 40.52 %
c. 60.42 %
d. 70.21 %
e. 79.96 %

Explanation:

Step1: Calculate molar mass of carbon in \(C_{10}H_{14}O\)

Molar mass of carbon (\(C\)) is \(12.01\ g/mol\). There are \(10\) carbon atoms. So mass of carbon \(=10\times12.01 = 120.1\ g/mol\)

Step2: Calculate mass percentage of carbon

Mass percentage of carbon \(=\frac{\text{Mass of carbon in compound}}{\text{Molar mass of compound}}\times100\)
Given molar mass of \(C_{10}H_{14}O = 150.2\ g/mol\)
Mass percentage \(=\frac{120.1}{150.2}\times 100\)
\(=\frac{12010}{150.2}=80\%\) (approx). More precisely \(\frac{120.1}{150.2}\times100=\frac{12010}{150.2}\approx 79.96\%\)

Answer:

E. \(79.96\%\)