Question

What is the mass of 3.45 moles of `NH_4NO_3`?

Answer 1

Shouldn't you tell us this?

Explanation:

The molar masses of hydrogen, nitrogen, and oxygen, are `1.00794, 14.01,` and `15.999*g*mol^-1` respectively. Sum these masses appropriately, multiply by 3.45, and report back if you're still unsure.

Answer 2

The mass of 3.45 moles `"NH"_4"NO"_3"` is 276 g.

Explanation:

First determine the molar mass of ammonium nitrate, `"NH"_4"NO"_3"`. Then multiply the given moles ammonium nitrate by its molar mass.

Molar mass `"NH"_4"NO"_3":` `"80.043 g/mol"`
https://www.ncbi.nlm.nih.gov/pccompound/?term=ammonium+nitrate

`(3.45cancel"mol NH"_4"NO"_3)xx(80.043"g NH"_4"NO"_3)/(1cancel"mol NH"_4"NO"_3)="276 g NH"_4"NO"_3"` rounded to three significant figure