Question

Oxygen oxidises ethyne to carbon dioxide and water as shown by the equation:

\[\ce{2C2H2 + 5O2 -> 4CO2 + 2H2O}\]

What volume of ethyne gas at STP required to produce 8.4 dm³ of carbon dioxide at STP?

[H = 1, C = 12, O = 16]

Answer 1

\[\ce{\underset{2 vol.}{2C2H2} + \underset{5 vol.}{5O2} -> \underset{4 vol.}{4CO2} + 2H2O}\]

4 vol. of O₂ required ethyne = 2 vol.

8.4 dm³ vol. of O₂ required ethyne = `(2 xx 8.4)/4`

= 4.2 dm³