Oxygen is about 20% of air (by volume). How many milliliters of air would contain 240 ml of oxygen?
ml of air (x)

Volume of air = 1200 ml

Given

20% Oxygen in air

240 ml Oxygen

Required

Volume of air

Solution

The concentration of a substance can be expressed in several quantities such as moles, percent (%) weight / volume,), molarity, molality, parts per million (ppm) or mole fraction. The concentration shows the amount of solute in a unit of the amount of solvent

240 ml = 20% Oxygen

volume of air :

= 100%/20% x 240 ml

= 1200 ml

Then the substance would be the first to run out which signifies the completing of the reaction.

Explanation: