Question

The gas in the discharge cell of a laser contains (in mole percent) 11% CO2, 5.3% N2, and 84% He. (a) What is the molar mass of this mixture

Answer 1

`MM_(mixture)=9.68g/mol`

Step-by-step explanation:

Hello!

In this case, since the molar mass of gaseous mixtures can be determined via a weighted average containing the molar mass of each gas and the mole fraction (mole percent divided by 100) as shown below:

`MM_(mixture)=x_(CO_2)M_(CO_2)+x_(N_2)M_(N_2)+x_(He)M_(He)`

Now, we plug in to obtain:

`MM_(mixture)=0.11*44g/mol+0.053*28+0.84*4\\\\MM_(mixture)=9.68g/mol`

Best regards!