Question

What volume of oxygen will be required to completely burn $160\text{mL}$ of acetylene, and what will be the volume of carbon dioxide so formed?

Answer 1

Step 1: Given Information

$160\text{mL}$ of acetylene

Step 2: Chemical Reaction

• Acetylene $\left({\mathrm{C}}_2{\mathrm{H}}_2\right)$ reacts with oxygen$\left({\mathrm{O}}_2\right)$ and results in the formation of carbon dioxide$\left({\mathrm{CO}}_2\right)$ and water$\left({\mathrm{H}}_2\mathrm{O}\right)$.
• The reaction involved is as follows:

${\mathrm{C}}_2{\mathrm{H}}_2\left(\mathrm{g}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)\to {\mathrm{CO}}_2\left(\mathrm{g}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$

Step 3: Balanced Chemical Reaction

• The balanced reaction is as follows:

$$\begin{gathered} 2{\mathrm{C}}_2{\mathrm{H}}_2\left(\mathrm{g}\right)+5{\mathrm{O}}_2\left(\mathrm{g}\right)\to 4{\mathrm{CO}}_2\left(\mathrm{g}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\text{l}\right) \\ 2\mathrm{vols}5\mathrm{vols}4\mathrm{vols}\mathrm{nil} \end{gathered}$$

Step 4: Calculation of volume of oxygen used

• From the balanced equation, it is clear that, $2$ volumes of acteylene require $5$ volumes of oxygen$\left({\mathrm{O}}_2\right)$.
• Therefore, $160\text{mL}$ of acteylene will require $\frac{5}{2}\times 160\mathrm{mL}=400\mathrm{mL}$ volume of oxygen.

Step 5: Calculation of volume of carbon dioxide produced

• From the balanced equation, it is clear that, $2$ volumes of acteylene produces $4$ volumes of carbon dioxide.
• Therefore, $160\text{mL}$ of acteylene will produce $\frac{4}{2}\times 160\mathrm{mL}=320\mathrm{mL}$ volume of carbon dioxide.

Therefore, $400\mathrm{mL}$ volume of oxygen is required and $320\mathrm{mL}$ volume of carbon dioxide is formed.