Question

What molarity of a 54.53 mL magnesium hydroxide solution is required to neutralize 77.16 mL of a 6.529 M solution of hydrochloric acid solution, which creates as products, magnesium chloride and water?

Answer 1

Number of moles present in hydrochloric acid solution = Volume of the solution in Liters * Molarity = (77.16/1000) Liter * 6.529 moles/ Liter = 0.504 moles

The balanced chemical equation between HCl and Mg(OH)₂ is:

2 HCl (aq) + Mg(OH)₂ (aq) = MgCl₂ (aq) + 2 H₂O (l)

From the reaction stoichiometry, we get:

Moles of Mg(OH)2 reacted = (1/2 )* Moles of HCl reacted

So, 0.504 moles of HCl reacts with (1/2) * 0.504 moles = 0.252 moles of Mg(OH)₂

Molarity of Mg(OH)₂ solution = Moles / Volume in Liters = 0.252 mole/ ( 54.53/1000) L = 4.619 mol/L

Molarity of magnesium hydroxide solution is : 4.619 M