Question

Nitrogen and oxygen gas react as illustrated by the equation given below:
N₂ (g) + O₂ (g) → 2NO
Calculate the volume of each reacting gas required to produce 1400 cm³ of nitric oxide.

Answer 1

According to the balanced chemical reaction, one mole of nitrogen and one mole of oxygen combine to form two moles of nitric oxide.
$\mathrm{Number}\mathrm{of}\mathrm{moles}\mathrm{of}{\mathrm{N}}_2=\mathrm{Number}\mathrm{of}\mathrm{moles}\mathrm{of}{\mathrm{O}}_2=\frac{\mathrm{Number}\mathrm{of}\mathrm{moles}\mathrm{of}\mathrm{NO}}{2}$
According to Avogadro's law, equal number of moles of reacting gases at a particular temperature occupy equal volume.
i.e.
$\mathrm{Volume}\mathrm{of}{\mathrm{N}}_2=\mathrm{Volume}\mathrm{of}{\mathrm{O}}_2=\frac{\mathrm{Volume}\mathrm{of}\mathrm{NO}}{2}$
Let us suppose that the volume of nitrogen is $x_{{\mathrm{N}}_2}$ litres, then the above relation can be written as:
$x_{{\mathrm{N}}_2}=x_{{\mathrm{O}}_2}=\frac{x_{\mathrm{NO}}}{2}$
We are given that volume of nitric oxide formed is 1400 cm³. Substituting this values in above equation, we get:
$x_{{\mathrm{N}}_2}=x_{{\mathrm{O}}_2}=\frac{1400}{2}=700{\mathrm{cm}}^3$

So, the volume of each reacting gas required to produce 1400 cm³ is 700 cm³.