Question

Air contains 21% (by volume) oxygen gas. The amount of oxygen gas in one litre of air at STP

Answer 1

Explanation:

Air contains 21% of oxygen gas.

Which means 21×1/100 = 0.21L

22.4L of O2 makes 32g

1L of O2 makes (32/22.4)g

0.21L will make(32×0.21/22.4)g

=0.3g of O2.

Hope it helps=)