If 30 mL of H2 and 20 mL of O2 reacts to form water, what is left at the end of the reaction ?

Question

If 30 mL of H2 and 20 mL of O2 reacts to form water, what is left at the end of the reaction ? (A) 10 mL of H2 (B) 5 mL of H2 (C) 10 mL of O2 (D) 5 mL of O2

Tardigrade Admin · Accepted Answer

underset2 vol2H2+ underset1volO2→ 2H2O 2 mole of H2 reacts with 1 vol of O2 to give water. Therefore. 30 mL of H2 will react with 15 mL of O2 to give water. Here, H2 is the limiting reactant. Volume of O2 left unreacted = 20-15 = 5 mL

Q. If 30 mL of $H_{2}$ and 20 mL of $O_{2}$ reacts to form water, what is left at the end of the reaction ?

10 mL of $H_{2}$

5 mL of $H_{2}$

10 mL of $O_{2}$

5 mL of $O_{2}$

$2 v o l 2 H_{2} + 1 v o l O_{2} \to 2 H_{2} O$
$2$ mole of $H_{2}$ reacts with $1$ vol of $O_{2}$ to give water. Therefore. $30 m L$ of $H_{2}$ will react with $15 m L$ of $O_{2}$ to give water. Here, $H_{2}$ is the limiting reactant.
Volume of $O_{2}$ left unreacted $= 20 - 15 = 5 m L$

Q. If 30 mL of H2​ and 20 mL of O2​ reacts to form water, what is left at the end of the reaction ?

10 mL of H2​

5 mL of H2​

10 mL of O2​

5 mL of O2​