Final answer:
The mole ratio between moles of magnesium consumed and moles of hydrogen formed is 1:1, per the balanced chemical equation that dictates the stoichiometry of the reaction.
Step-by-step explanation:
To determine the mole ratio between the moles of magnesium consumed and the moles of hydrogen formed, we first consider the balanced chemical equation for the reaction of magnesium with a substance such as hydrochloric acid (which is assumed based on the mention of magnesium chloride and hydrogen in the question):
Mg + 2HCl → MgCl₂ + H₂
From the equation, we see that 1 mole of magnesium reacts with 2 moles of hydrochloric acid to produce 1 mole of magnesium chloride and 1 mole of hydrogen gas. This gives us the stoichiometric mole ratios for the reactants and products. As the equation shows a 1:1 ratio between magnesium and hydrogen, the mole ratio we are looking for is also 1:1. This ratio is independent from the information provided (a, b, c, d above) since these details describe the products and do not directly affect the stoichiometry of the reactants in determining the ratio of magnesium to hydrogen.
Regardless of the amounts of magnesium consumed and hydrogen produced, the absolute mole ratio of magnesium to hydrogen is always 1:1, assuming complete reaction and that magnesium is the limiting reactant. Actual amounts react according to this fixed ratio by mole, as defined by the balanced chemical equation, which is a direct application of the law of conservation of mass and the law of definite proportions.