Q. The number of moles of oxygen in one litre of air containing 21% oxygen by volume, in standard conditions, is
A) 0.186 mol
B) 0.21 mol
C) 2.10 mol
D) 0.0093 mol
Explanation
(d)
In 1 L air, volume of $O_{2} = 210\ cc$
$\because$ 22400 $cm^{3} = 1$ mol
$\therefore$ 210 $cm^{3} = \frac{210}{22400} = 0.0093$ mol
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.