The number of moles of oxygen in one litre ofair containing 21% oxygen

1.	The number of moles of oxygen in one litre ofair containing 21% oxygen by volume, understandard conditions, is(a) 0.0093 mol(c) 0.186 mol(b) 2.10 mol(d) 0.21 mol.
Answer» in 1L of air... 21% is oxygen so, volume of oxygen is 0.21L now in 1 mol ---- 22.4 l is there.. so, for 0.21 l , the no..of moles = 0.21/22.4 = 0.009375..moles option A.

The number of moles of oxygen in one litre ofair containing 21% oxygen by volume, understandard conditions, is(a) 0.0093 mol(c) 0.186 mol(b) 2.10 mol(d) 0.21 mol.

Answer»

in 1L of air... 21% is oxygen

so, volume of oxygen is 0.21L

now in 1 mol ---- 22.4 l is there..

so, for 0.21 l , the no..of moles = 0.21/22.4 = 0.009375..moles

option A.