Question

The mole fraction of oxygen in a mixture of 7g of nitrogen and 8g og oxygen is?

Answer 1

mole fraction of oxygen in the mixture will be 1/2 as mole fraction=total no. of moles of A/moles of A + moles of B
where A+B is the mixture

Answer 2

Given:

A mixture has 7g of nitrogen and 8g of oxygen.

To find:

The mole fraction of oxygen.

Solution:

The atomic weight of nitrogen is 14 grams and the atomic weight of oxygen is 16 grams.

Hence the number of moles of nitrogen is 7/14=0.5 moles.

Hence the number of moles of oxygen is 8/16=0.5 moles.

Hence the mole fraction of oxygen is given as-

The number of moles of oxygen/total number of moles.

$\frac{0.5}{0.5 + 0.5} \\ = 0.5$

The mole fraction of oxygen is 0.5.