This problem is providing us with the mass of an unknown element which produces 43.5 g of M3N2. Thus, its name and molar mass are required and found to be 4.02 g/mol and calcium nitride after the following:
Stoichiometry.In chemistry, stoichiometry is a tool used for the calculation of masses or moles involved in chemical reactions, by the utilization of molar masses and mole ratios based on proportional factors.
In such a way, for the given reaction, one can use the formulas to write the following balanced chemical equation:
Where there is a 3:1 mole ratio of the metal to the product, which means we can use the following stoichiometric setup:
Now, by using the numbers only, one will be able to calculate x as the atomic mass of the element M in g/mol:
Which matches with the molar mass of calcium. Moreover, we find its name as calcium nitride.
Learn more about stoichiometry: