Question

The number of gram-molecule of oxygen which contain $6.02\times {10}^{24}CO$ molecules is

• A. 10 g molecule
• B. 5 g molecule
• C. 1 g molecule
• D. 0.5 g molecule

Answer 1

The correct option is B 5 g molecule

Number of oxygen atoms = Number of CO molecules $=6.022\times {10}^{24}$
Number of oxygen molecule
$=\frac{1}{2}\times \text{number of oxygen atoms}=\frac{1}{2}\times 6.022\times {10}^{24}=3.011\times {10}^{24}$
Number of gram molecule of $O_2$ molecules
$=\frac{3.011\times {10}^{24}}{6.022\times {10}^{23}}=5$ g molecule