Answer:
120 moles of Mg
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
3Mg + 2H₃PO₄ —> Mg₃(PO₄)₂ + 3H₂
From the balanced equation above,
3 moles of Mg reacted to produce 3 moles of H₂.
Finally, we shall determine the number of mole of Mg needed to produce 120 moles of H₂. This can be obtained as follow:
From the balanced equation above,
3 moles of Mg reacted to produce 3 moles of H₂.
Therefore, 120 moles of Mg will also react to produce 120 moles of H₂.
Thus, 120 moles of Mg is needed for the reaction.
