Question

a hydrocarbon has the formula c₂h₄. what is the percent by mass of carbon in the compound? (c= 12.01 amu; h = 1.008amu) 1) 33.3% 2) 50.0% 3) 62.4% 4) 85.6% 5) 92.1%

Explanation:

Step1: Calculate mass of C

There are 2 C atoms. Mass of C = \(2 \times 12.01 = 24.02\) amu.

Step2: Calculate mass of H

There are 4 H atoms. Mass of H = \(4 \times 1.008 = 4.032\) amu.

Step3: Calculate molar mass

Molar mass of \(C_2H_4\) = \(24.02 + 4.032 = 28.052\) amu.

Step4: Calculate % mass of C

% mass of C = \(\frac{24.02}{28.052} \times 100 \approx 85.6\%\).

Answer:

1. 85.6%