# Question 4c11e

Jan 10, 2018

$1.28 g$ of isocane.

#### Explanation:

${C}_{20} {H}_{42}$ is called isocane.

It has a molar mass of $282.5475 g \text{/} m o l$.

This means, in $4.52 \cdot {10}^{-} 3$ moles of isocane, there is

$282.5475 g \cdot 4.52 \cdot {10}^{-} 3 = 1.28 g$ of isocane.

Jan 10, 2018

$\text{1.28 g}$

#### Explanation:

Calculate the molar mass of ${\text{C"_20"H}}_{42}$ by taking

$20 \times \left(\text{molar mass C") + 42xx("molar mass H}\right)$

This gives

$20 \times \text{12.011 g/mol" + 42xx"1.0079 g/mol" = "282.5518 g/mol}$

Now, take the molar mass and multiply it by the number of moles.

("282.5518 g/mol") xx (4.52 * 10^-3 quad "moles")= "1.277134 g"#

Rounded to three sig figs, this is $\text{1.28 g}$.