Question

The volume of oxygen gas at STP required for the complete combustion of 200 mL of acetylene gas at STP (1 atm, 273 K) is:

Answer 1

The reaction is represented as:
$2C_2{H}_2+5O_2\to 4C{O}_2+2H_{2}O$
2 moles of acetylene requires 5 moles of oxygen
$\Rightarrow 2\times 22400$ mL of acetylene requires $5\times 22400$ mL of oxygen at STP
volume of oxygen required for 200 mL of acetylene at STP =
$\frac{5\times 22400}{2\times 22400}\times 200=500$ mL