Answer:
26.95 %
Explanation:
Air contains the highest percentage of oxygen and nitrogen gases. Magnesium then combines with both of the gases:
Firstly, find the total number of moles of magnesium metal:
Let's say that x mol react in the first reaction and y mol react in the second reaction. This means:
According to stoichiometry, we form:
Multiplying moles by the molar mass of each substance will yield mass. This means we form a total of:
The total mass is given, so we have our second equation to solve:
We have two unknowns and two equations, we may then solve:
Express y from the first equation:
Substitute into the second equation:
Moles of nitride formed:
Convert this to mass:
Find the percentage: