Finding Density using STP and Molar Mass

[dredre]

Homework Statement

What is the density of ammonia gas (molar mas of 17.03) at STP?

Homework Equations

d=m/v
pv=nrt

The Attempt at a Solution

So, i know that to find density, i need to have volume (d=m/v). To begin with, I plugged in my values into pv=nrt only to realize that i was missing moles. this might just be a chem issue, but can anyone refresh me on how to find the moles using the given? :/

 

[ehild]

n is the number of moles, m/M where M is the molar mass.

ehild

 

[Borek]

If you have problem finding the answer you can always assume volume of 1 L, or number of moles to be 1 - and continue from there, for some people it simplifies the calculations. But in general when solving using just symbols you will get the same result, if the problem can be solved extensive properties will cancel out in the end.