Question

When magnesium metal and an aqueous solution of hydrochloric acid combine, they produce an aqueous solution of magnesium chloride and hydrogen gas. Using the equation, Mg (s) + 2HCl (aq) → MgCl2 (aq) + H2 (g), if 24.3 g of Mg and 75.0 g of HCl are allowed to react, calculate the mass of MgCl2 that is produced

Answer 1

Mg + 2 HCl ------------------------> MgCl2 + H2

24g       71g                                  95 g

24.3g     75g                                   x

first we need to find limiting reagent

24 g Mg ------------------> 71 g HCl

x g Mg --------------------> 75 g HCl

x = 24 x 75 / 71 = 25.35g Mg needed for 75 g HCl . so HCl is limiting reagent

so the product formed is based on limiting reagent

24 g Mg gives ---------------------> 95 g MgCl2

24.3 g Mg gives -------------------> y g MgCl2

y = 24.3 x 95 / 24

y =96.19 g

MgCl2 mass produced = 96.19 g