Question

Question #e9b89

Answer 1

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 `"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

`"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 `"26 g"`, you can say that its molar mass is equal to

`color(darkgreen)(ul(color(black)("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.