Question

What mass of HCl is neutralized by 3.33 g Mg(OH)2?

Answer 1

First, you write the balanced equation for the reaction

2HCl + Mg(OH)2 ----->MgCl2 + 2H2O


Next, find the number of moles of Magnesium Hydroxide

Number of moles of Mg(OH)2 =

mass / Mr = 3.33 / 24 +2(1+16)
=0.0574 mol

Find the mole ratio between HCl and Mg(OH)2 which is 1:2

Number of moles of HCl = 0.0574 x 2 = 0.1148 mol

Mass of HCl = Mr x no. of moles
=0.1148 x (1+35.5)
=4.19 g