# Question e9b89

Jun 9, 2017

Here's what I got.

#### Explanation:

The molar mass of a compound is essentially the mass of $1$ mole of said compound, so all you have to do here is figure out how many grams you get for $1$ mole of your unknown compound.

You know that $10$ moles of this compound have a mass of $\text{260 g}$, so you must determine what mass would make this ratio

(color(blue)(?)color(white)(.)"g")/"1 mole" -> the molar mass of the compound

equivalent to

$\text{260 g"/"10 moles}$

Set up the equation as

(color(blue)(?)color(white)(.)"g")/"1 mole" = "260 g"/"10 moles"

Rearrange to find

color(blue)(?) = (1 color(red)(cancel(color(black)("mole"))))/(10color(red)(cancel(color(black)("moles")))) * "260 g"

color(blue)(?) = "26 g"#

So, if $1$ mole of this compound has a mass of $\text{26 g}$, you can say that its molar mass is equal to

$\textcolor{\mathrm{da} r k g r e e n}{\underline{\textcolor{b l a c k}{{\text{molar mass" = "26 g mol}}^{- 1}}}}$

I'll leave the answer rounded to two sig figs, but keep in mind that you only have one significant figure for the number of moles present in your sample.