# Question 68773

Mar 29, 2017

Here's what I got.

#### Explanation:

We can determine the mass of any number of moles of a given substance by using that substance's molar mass. The molar mass represents the mass of exactly $1$ mole of a substance.

In this case, carbon dioxide has a molar mass of $\textcolor{b l u e}{\text{44.0 g}}$ $\textcolor{\mathrm{da} r k \mathmr{and} a n \ge}{{\text{mol}}^{- 1}}$. This means that $\textcolor{\mathrm{da} r k \mathmr{and} a n \ge}{1}$ mole of carbon dioxide has a mass of $\textcolor{b l u e}{\text{44.0 g}}$.

Consequently, $3$ moles of carbon dioxide will have a mass of

3 color(red)(cancel(color(black)("moles CO"_2))) * color(blue)("44.0 g")/(color(darkorange)(1)color(red)(cancel(color(black)("mole CO"_2)))) = "132 g"#

You should round this off to one significant figure, the number of sig figs you have for the number of moles of carbon dioxide present in your sample, but I'll leave the answer rounded to two sig figs

$\textcolor{\mathrm{da} r k g r e e n}{\underline{\textcolor{b l a c k}{\text{mass of 3 moles CO"_2 = "130 g}}}}$