Question

$2500$ cc of oxygen was burnt with $600$ cc ethane $\left[C_2{H}_6\right]$. Calculate the volume of unused oxygen and the volume of carbon dioxide formed.

Answer 1

$\underset{2V}{C_2{H}_6}+\underset{7V}{7O_2}⟶4\underset{4V}{C{O}_2}+6H_{2}O$

From the above reaction,

Amount of oxygen to react with $2V$ of ethane $=7V$

Given volume of ethane $=600cc$

$\therefore$ Amount of oxygen to react with $600cc$ of ethane $=\frac{7}{2}\times 600=2100cc$

Given voume of oxygen $=2500cc$

$\therefore$ Amount of oxygen left after reacting with $600cc$ of ethane $=2500-2100=400cc$

Now, again fromthe reaction,

Amount of $C{O}_2$ formed in the combustion of $2V$ of ethane $=4V$

Given volume of ethane $=600cc$

$\therefore$ Amount of $C{O}_2$ formed in the combustion of $600cc$ of ethane $=\frac{4}{2}\times 600=1200cc$

Hence the volume of unused oxygen is $400cc$ and the volume of carbon dioxide formed is $1200cc$.