Question

Calcium carbide is used for the artificial ripening of fruits. Actually the fruit ripens because of the heat evolved while calcium carbide reacts with the moisture. During this reaction calcium hydroxide and acetylene gas are formed. If 200 cm³ of acetylene is formed from a certain mass of calcium carbide, find the volume of oxygen required and carbon dioxide formed during the complete combustion. The combustion reaction can be represented as below.

\[\ce{2C2H2_{(g)} + 5O2_{(g)}-> 4CO2_{(g)} + 2H2O_{(g)}}\]

Answer 1

Applying Gay-Lussac's law on the equation,

\[\ce{\underset{2 Vol.}{2C2H2_{(g)}} + \underset{5 Vol.}{5O2_{(g)}}-> \underset{4 Vol.}{4CO2_{(g)}} + 2H2O_{(g)}}\]

As 2 volumes of acetylene require = 5 volumes of oxygen

1 volume of acetylene require = `5/2` volumes of oxygen

∴ 200 cm³ of acetylene will require = `5/2 xx 200`

= 500 cm³ of oxygen

Further, 2 volumes of acetylene produce = 4 volumes of CO₂

1 volume of acetylene produce = `4/2` volumes of CO₂

∴ 200 cm³ of acetylene will produce = `4/2 xx 200`

= 400 cm³ of CO₂
Hence, 500 cm³ of oxygen and 400 cm³ of carbon dioxide is formed.