# Question d3fd1

Jun 14, 2017

The molecular formula of $\text{C"_2"H"_5}$ is color(blue)("C"_4"H"_10".

The molecular formula of $\text{CH}$ is color(blue)("C"_6"H"_6.

#### Explanation:

In order to determine the molecular formula from an empirical formula, first determine the empirical formula mass. Then divide the given molecular mass by the empirical formula mass.

color(blue)("Empirical Formula Mass of C"_2"H"_5".

$\text{C} :$(2xx12"g/mol")="24 g/mol"

$\text{H} :$(5xx1"g/mol")="5 g/mol"

Formula Mass = $\text{24 + 5 g/mol = 29 g/mol}$

color(blue)("Molecular Formula of C"_2"H"_5"

Divide the molecular mass by the empirical mass.

$\frac{58}{29} = 2$

Multiply the subscripts in the empirical formula by $2$ to get the molecular formula.

${\text{C"_4"H}}_{10}$

color(blue)("Empirical Formula Mass of CH".

$\text{C} :$$1 \times 12 \text{g/mol}$

$\text{H} :$$1 \times 1 \text{g/mol}$

Formula Mass = $\text{12 g/mol+1 g/mol=13 g/mol}$

Divide the molecular mass by the empirical mass.

$\frac{78}{13} = 6$

color(blue)("Molecular Formula of CH"#.

Multiply the subscripts of $\text{CH}$ by $6$.

$\text{C"_6"H"_6}$