Question

The reaction :

$2C+O_2\to 2CO$

is carried out by taking $24g$ of carbon and $96$ g $O_2$. The number of moles of oxygen left unreacted is :

Answer 1

In the given reaction:

$2C+O_2\to 2CO$

2 moles of $C$ is reacting with 1 mole of $O_2$.

Or, we can say 24 g of $C$ reacts with 32 g of oxygen

The total mass of oxygen $=96g$

Mass of oxygen left unreaction $=96-32=64g$

Therefore, number of moles left unreacted $=\frac{64}{32}=2moles$