Question

What is the mass of one molecule of oxygen?

• A. $5.31\times {10}^{-23}g$
• B. $5.33\times {10}^{23}g$
• C. $5.25\times {10}^{23}g$
• D. $5.02\times {10}^{-23}g$

Answer 1

Answer: (A)

$5.31\times {10}^{-23}g$

The molecular weight of oxygen is 32 g/mol.

Hence, one mole of oxygen weighs 32 g.

One mole of oxygen contains $6.023\times {10}^{23}$ molecules.

The mass of one molecule of oxygen is:

$\frac{32}{6.023\times {10}^{23}}=5.31\times {10}^{-23}$ g.

Hence, option $A$ is correct.