Question

Milk of magnesia can be used to relieve indigestion and heartburn. The active ingredient in this substance is magnesium hydroxide, Mg(OH)₂ What is the percent composition of

magnesium hydroxide in this substance?
A 20.0% Mg. 40.0% 0,40.0% H

B. 43.1% Mg. 51.3% 0, 5.6 % H

C. 41.7% Mg. 54.9% 0, 3.4% H

D 47.1% Mg, 48.3 % 0, 4.1% H

Answer 1

Answer:Therefore, the percent composition of magnesium hydroxide in milk of magnesia is option C: 41.7% Mg, 54.9% O, 3.4% H.

Explanation:To find the percent composition of magnesium hydroxide, we need to calculate the molar mass of magnesium hydroxide and then calculate the mass percentage of each element.Mg(OH)₂ has a molar mass of:1 x Mg = 24.31 g/mol

2 x O = 15.99 g/mol x 2 = 31.98 g/mol

2 x H = 1.01 g/mol x 2 = 2.02 g/molTotal molar mass = 24.31 + 31.98 + 2.02 = 58.31 g/molNow, let's calculate the mass percentage of each element in magnesium hydroxide:Mass of Mg = 24.31 g/mol / 58.31 g/mol x 100% = 41.7%Mass of O = 31.98 g/mol / 58.31 g/mol x 100% = 54.9%Mass of H = 2.02 g/mol / 58.31 g/mol x 100% = 3.4%