# How do you solve gas laws problems with the given "at STP" and with mass?

##### 1 Answer

I like to use the Ideal Gas Law.

#### Explanation:

The **Ideal Gas Law** is:

#color(blue)(bar(ul(|color(white)(a/a)PV = nRTcolor(white)(a/a)|)))" "#

where

#P# is the pressure#V# is the volume#n# is the number of moles#R# is the universal gas constant#T# is the temperature

We can rearrange the Ideal Gas Law to get

#V = (nRT)/P#

Also,

∴

**EXAMPLE**

What is the volume of 10.0 g of hydrogen at STP?

**Solution**

Remember that STP is defined as 0 °C and 1 bar.