Question

How many Oxygen molecules are needed to synthesise 0.245 g of Carbon monoxide by controlled reaction with carbon?

Answer 1

$C+\frac{1}{2}{O}_2\to CO$

$1mole$ carbon required $0.5mole{O}_2$ to produce $1moleCO$

Moles of $CO=\frac{0.245}{28}=8.75\times {10}^{-3}$

Moles of oxygen required $=\frac{8.75\times {10}^{-3}}{2}=4.375\times {10}^{-3}$

Number of $O_2$ molecules $=N_A\times molesof{O}_2$

$=6.02\times {10}^{23}\times 4.375\times {10}^{-3}$

$=2.63375\times {10}^{21}molecules$