The number of moles of oxygen present in one litre of air under standard conditions (it contains 21% oxygen) is:

Question

The number of moles of oxygen present in one litre of air under standard conditions (it contains 21% oxygen) is: (A) 0.246 mole (B) 0.07438 mole (C) 2.0078 mole (D) 0.0093 mole

Tardigrade Admin · Accepted Answer

Air contains 21% of oxygen ∴ volume of oxygen =(21/100)= 0.21 litre ∴ Number of moles of oxygen present in 0.21 litre at NTP =(0.21/22.4)=0.0093

Q. The number of moles of oxygen present in one litre of air under standard conditions (it contains 21% oxygen) is:

0.246 mole

0.07438 mole

2.0078 mole

0.0093 mole

Air contains 21% of oxygen $∴$ volume of oxygen $= \frac{21}{100} =$ 0.21 litre $∴$ Number of moles of oxygen present in 0.21 litre at NTP $= \frac{0.21}{22.4} = 0.0093$

Q. The number of moles of oxygen present in one litre of air under standard conditions (it contains 21% oxygen) is:

0.246 mole

0.07438 mole

2.0078 mole

0.0093 mole

Air contains 21% of oxygen ∴ volume of oxygen =10021​= 0.21 litre ∴ Number of moles of oxygen present in 0.21 litre at NTP =22.40.21​=0.0093

Air contains 21% of oxygen $∴$ volume of oxygen $= \frac{21}{100} =$ 0.21 litre $∴$ Number of moles of oxygen present in 0.21 litre at NTP $= \frac{0.21}{22.4} = 0.0093$