# Question #8b6ce

##### 1 Answer

By using the Ideal Gas Law equation (

#### Explanation:

Look at the given, you were given the Pressure (P), Temperature (T), Volume (V) and mass (m) of an unknown gas.

P = 79.97 kPa

V = 4.167 L

T =

m= 20.83 g

Based on the given, you can definitely use the Ideal Gas Law equation to find the molar mass of the gas, where R is a constant equal to

But first, we need to convert units:

P =

V =

T =

m=

Now we are ready to compute.

n = **0.1322 mol**

Since molar mass is defined as weight of substance over the number of moles substance or

MM =

then

MM =

MM =

Therefore, the molar mass of the unknown gas is 157.56 g/mol.