Problem: Dichloroethane, a compound that is often used for dry cleaning, contains carbon, hydrogen, and chlorine. It has a molar mass of 99 g/mol. Analysis of a sample shows that it contains 24.3% carbon and 4.1% hydrogen. What is its molecular formula?

FREE Expert Solution

Given the mass percent of:

• C = 24.3 % C
• H = 4.1 % H

$\mathbf{100}\mathbf{%}\mathbf{=}\mathbf{%}\mathbf{C}\mathbf{+}\mathbf{%}\mathbf{H}\mathbf{+}\mathbf{%}\mathbf{Cl}\phantom{\rule{0ex}{0ex}}\mathbf{100}\mathbf{%}\mathbf{=}\mathbf{24}\mathbf{.}\mathbf{3}\mathbf{%}\mathbf{+}\mathbf{4}\mathbf{.}\mathbf{1}\mathbf{%}\mathbf{+}\mathbf{%}\mathbf{Cl}\phantom{\rule{0ex}{0ex}}\mathbf{%}\mathbf{Cl}\mathbf{=}\mathbf{100}\mathbf{%}\mathbf{-}\mathbf{24}\mathbf{.}\mathbf{3}\mathbf{%}\mathbf{-}\mathbf{4}\mathbf{.}\mathbf{1}\mathbf{%}$

% Cl = 71.6%

Assuming we have 100 g of the compound:

• 24.3 g C
• 4.1 g H
• 71.6 g Cl

The atomic masses are 12.01 g/mol C, 1.01 g/mol H, 35.45 g/mol Cl.

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Problem Details

Dichloroethane, a compound that is often used for dry cleaning, contains carbon, hydrogen, and chlorine. It has a molar mass of 99 g/mol. Analysis of a sample shows that it contains 24.3% carbon and 4.1% hydrogen. What is its molecular formula?