Question

How many grams of magnesium metal will react completely with 6.3 liters of 4.5 M HCl? Show all of the work needed to solve this problem.

Mg (s) + 2 HCl (aq) yields MgCl2 (aq) + H2 (g)

Answer 1

Mg (s) + 2 HCl (aq) -> MgCl2 (aq) + H2 (g)

1) Number of mols of HCl, n

n = 6.3 L * 4.5 mol/L = 28.35 mol

2) ratio: 2 mol HCl / 1 mol Mg = 28.35 mol HCl / x mol Mg

x = 28.35 mol HCL * 1 mol Mg / 2 mol HCL = 14.175 mol Mg

3) Convert mol to mass using atomic mass of Mg

14.175 mol Mg * 24.3 g Mg / mol Mg = 344. 45 g

Answer: 344.45 g