Homework Help

If 4g of a gas occupied 11.2L at 0C and 0.25atm calculate molecular mass of the gas....

user profile pic

roshan-rox | Valedictorian

Posted June 24, 2013 at 5:18 AM via web

dislike 1 like

If 4g of a gas occupied 11.2L at 0C and 0.25atm calculate molecular mass of the gas.

A)8

B)16

C)32

D)48

E)64

1 Answer | Add Yours

user profile pic

jeew-m | College Teacher | (Level 1) Educator Emeritus

Posted June 24, 2013 at 5:41 AM (Answer #1)

dislike 1 like

We can use ideal gas law here. We have the following data.

`P = 0.25atm`

`V = 11.2L`

`R = 0.08206(atmL)/(molK)`

`T = 273K`

 

`PV = nRT`

`n = (PV)/(RT)`

`n = (0.25xx11.2)/(273xx0.08206)`

`n = 0.125mol`

 

If the molecular mass of the gas is M;

`M = (mass)/(mol)`

`M = 4/0.125`

`M = 32g/(mol)`

 

So the molecular mass of the gas is `32g/(mol)` . Answer is C).

This looks like `O_2` gas.

 

Note

We assume the gas is an ideal gas.

Sources:

Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes