# What is the molar mass of 31.3 g of gas exerting a pressure of 5.71 atm on the walls of a 3.04 L container at 297 K?

##### 2 Answers

The molar mass of the gas is

#### Explanation:

Use the ideal gas law

Notice that number of moles is

Plug it into the ideal gas law for

Rearrange and isolate x.

Plug everything in (excluding units)

(If you cancel out all the units, you will find that you will get

The molar mass of the gas is

#### Explanation:

Use the ideal gas law equation to determine moles. Then divide the given mass by the moles to get molar mass.

where:

**Organize the data:**

**Known**

**Unknown**

**Calculate moles**

Rearrange the ideal gas law equation to isolate

**Determine molar mass**

Divide the given mass by the calculated moles.