Mass - volume stoichiometry involves the quantities of substances in terms of mass and volume both.
Either the volume of a gas is necessary to be found corresponding to the given mass of a substance, or the mass of a substanvce is to be calculated corresponding to the given volume of a gas.
Use is made of the fact that each mole corresponds to a molar mass of a substance and also to 22.4 dm3 volume of a gaseous substance at STP.
Solving problems involving mass-volume relationships, are done as follows;
(1) balanced equation is written for the reaction.
(2) Write the number of moles below the formulae of relevant substances.
(3) Convert moles into masses and volumes as required.
(4) Calculate the unknown quantity.