Question

Mass percentage ratio '$\mathrm{C}$‘ and ’ $\mathrm{H}$‘ and ’$\mathrm{C}$‘ and ’$\mathrm{O}$' of saturated acyclic organic compound in $4:1$ and$3:4$. What is the number of moles of oxygen required for combustion for two moles of organic compound "X"?

Answer 1

Step 1:

• Ratio of $\mathrm{C}:\mathrm{H}$=$4:1$
• Ratio of $\mathrm{C}:\mathrm{O}$=$3:4$

Step 2:

• Multiplying $\mathrm{C}:\mathrm{H}$ ratio with $3$$=12:3$
• Multiplying $\mathrm{C}:\mathrm{O}$ratio with $4=12:16$
• Mass ratio of $\mathrm{C}:\mathrm{H}:\mathrm{O}$$=12:3:16$
• Mole ratio of $\mathrm{C}:\mathrm{H}:\mathrm{O}$ $=1:3:1$

Step 3:

• Empirical formula$={\mathrm{CH}}_3\mathrm{O}$
• Molecular formula$={\mathrm{C}}_2{\mathrm{H}}_6{\mathrm{O}}_2$
• ${\mathrm{C}}_2{\mathrm{H}}_6{\mathrm{O}}_2\left(\mathrm{s}\right)+\frac{5}{2}{\mathrm{O}}_2\left(\mathrm{g}\right)\to 2{\mathrm{CO}}_2\left(\mathrm{g}\right)+3{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$
• So moles of oxygen required are $5$moles.

Therefore, $5$ moles is the number of moles of oxygen required for combustion for two moles of organic compound "X