Question

Equal masses of methane and oxygen are mixed in an empty container at 25 degree celsius the fraction of total pressure exerted by oxygen is ?
a. 2/3
b. 1/3*273/298
c. 1/3
d. 1/2 ​

Answer 1

Answer:

1/3

Explanation:

Equal masses of methane and oxygen are mixed in an empty container at 25

o

C. The fraction of the total pressure exerted by oxygen is

3

1

.

Let 32 g of oxygen are mixed with 32 g of methane.

The molar masses of methane and oxygen are 16 g/mol and 32 g/mole respectively

The number of moles of methane =

16g

32g

=2moles.

The number of moles of oxygen =

32g

32g

=1mole.

Total number of moles =2+1=3.

The mole fraction of oxygen =

1+2

1

=

3

1

.

The mole fraction is proportional to the fraction of the total pressure exerted.

Hence, the fraction of the total pressure exerted by oxygen is

1/3

Answer 2

The correct answer is 1/3