NEET Questions Solved


The number of moles of oxygen in 1L of air containing 21% oxygen by volume, under standard conditions, is 

(a) 0.0093 mole

(b) 2.10 moles

(c) 0.186 mole

(d) 0.21 mole

(a) Volume oxygen in 1L of air = 21/100x1000 = 210mL

22400 mL volume at STP is occupied by oxygen = 1mole

Therefore, number of moles occupied by 210mL = 210/22400 = 0.0093mol

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