Question

Oxygen oxidises Ethyne to Carbon dioxide and water as shown by the equation
$2{\mathrm{C}}_2{\mathrm{H}}_2+5{\mathrm{O}}_2\to 4{\mathrm{CO}}_2+2{\mathrm{H}}_2\mathrm{O}$
What volume of Ethyne gas at STP is required to produce $8.4{\mathrm{dm}}^3$ of carbon dioxide at STP?
(H=1, C=12 and O=16)

Answer 1

Step 1: Given data:-

The volume of carbon dioxide $8.4{\mathrm{dm}}^3$.

The atomic mass of hydrogen, carbon, oxygen are 1, 12 ,16 respectively.

Step 2: Applying Avogadro's law:-

$\underset{2\mathrm{vol}:5\mathrm{vol}:4\mathrm{vol}:2\mathrm{vol}}{\underset{\mathrm{Ethyne}}{2{\mathrm{C}}_2{\mathrm{H}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Oxygen}}{5{\mathrm{O}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Carbon}\mathrm{dioxide}}{4{\mathrm{CO}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Water}}{2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}}$

Step 3: Calculating volume of ehyne:-

From the above equation if, 4 vol. of Carbon dioxide is produced by 2 vol. of Ethyne

$\therefore$$8.4{\mathrm{dm}}^3$of Carbon dioxide will need $\frac{2}{4}\times 8.4=4.2d{m}^3$of Ethyne

Therefore, the volume of Ethyne gas required to produce $8.4{\mathrm{dm}}^3$ of Carbon dioxide at STP is $4.2{\mathrm{dm}}^3$.