2H\(_2\) + O\(_2\) → 2H\(_2\)O

From the equation above, calculate the volume of unreacted oxygen gas if a mixture of 50cm\(^3\) of hydroden and 75cm\(^3\) of oxygen are involved

A.

85cm\(^3\)

B.

50cm\(^3\)

C.

125cm\(^3\)

D.

55cm\(^3\)

Correct answer is B

Since 2 mol H\(_2\) reacted with 1 mol of O\(_2\)

: 50cm\(^3\) of hydrogen reacted with 25cm\(^3\) of oxygen

Remainder oxygen = Supplied amount - Reacted amount → 75cm\(^3\) - 25cm\(^3\)

= 50cm\(^3\)