Answer:
0.062 moles of hydrogen gas
Explanation:
We must first out down the reaction equation before we can attempt to solve the problem.
Mg(s) + 2HCl(aq) ----> MgCl2(aq) + H2(g)
Next we obtain the number of moles in 1.5 g of magnesium metal from;
Molar mass of magnesium = 24.3 gmol-1
Number of moles of magnesium= mass/molar mass = 1.5g/24.3gmol-1 = 0.062 moles
From the reaction equation;
1 mole of magnesium metal yields 1 mole of hydrogen gas
0.062 moles of magnesium metal will yield 0.062 moles of hydrogen gas
Therefore, reaction of 1.5g of magnesium metal with excess hydrochloric acid will yield 0.062 moles of hydrogen gas.
