The equation,
4NH3 + 5O2 ⟶ 4NO + 6H2O
represents the catalytic oxidation of ammonia. If 100 cm3 of ammonia is used, calculate the volume of oxygen required to oxidise the ammonia completely.
[By Lussac's law]
4NH3+5O2⟶4NO+6H2O4 vol.:5 vol.⟶4 vol.\begin{matrix} 4\text{NH}_3 & + & 5\text{O}_2 &\longrightarrow & 4\text{NO} & + & 6\text{H}_2\text{O} \\ 4 \text{ vol.} & : & 5 \text{ vol.} & \longrightarrow & 4\text{ vol.} \end{matrix}4NH34 vol.+:5O25 vol.⟶⟶4NO4 vol.+6H2O
To calculate the volume of oxygen required :
NH3:O24 vol.:5 vol.100 cm.3:x\begin{matrix}\text{NH}_3 & : & \text{O}_2 \\ 4 \text{ vol.} & : & 5 \text{ vol.} \\ 100 \text{ cm.}^3 & : & \text{x} \end{matrix}NH34 vol.100 cm.3:::O25 vol.x
∴x=54×100=125 cm3\therefore x = \dfrac{5}{4} \times 100 = 125 \text{ cm}^3∴x=45×100=125 cm3
Hence, volume of oxygen required = 125 cm3
