Question

1. vitamin e many plants contain vitamin e (c₂₉h₅₀o₂), a substance that some think slows the aging process in humans. what is the percent composition of vitamin e?

Explanation:

Step1: Calculate molar mass of vitamin E

The molar mass of $C_{29}H_{50}O_{2}$:
The molar mass of carbon ($C$) is approximately $12.01\ g/mol$, hydrogen ($H$) is approximately $1.01\ g/mol$ and oxygen ($O$) is approximately $16.00\ g/mol$.
$M = 29\times12.01+50\times1.01 + 2\times16.00$
$M=348.29+50.5+32.00$
$M = 430.79\ g/mol$

Step2: Calculate percent - composition of carbon

The mass of carbon in one mole of vitamin E is $m_C=29\times12.01 = 348.29\ g$.
The percent - composition of carbon, $\%C=\frac{348.29}{430.79}\times100\%\approx80.85\%$

Step3: Calculate percent - composition of hydrogen

The mass of hydrogen in one mole of vitamin E is $m_H = 50\times1.01=50.5\ g$.
The percent - composition of hydrogen, $\%H=\frac{50.5}{430.79}\times100\%\approx11.72\%$

Step4: Calculate percent - composition of oxygen

The mass of oxygen in one mole of vitamin E is $m_O=2\times16.00 = 32.00\ g$.
The percent - composition of oxygen, $\%O=\frac{32.00}{430.79}\times100\%\approx7.43\%$

Answer:

The percent - composition of vitamin E is approximately $80.85\%$ carbon, $11.72\%$ hydrogen and $7.43\%$ oxygen.