# An antacid contains 200 mg of aluminum hydroxide and 200 mg of magnesium hydroxide per capsule....

## Question:

An antacid contains 200 mg of aluminum hydroxide and 200 mg of magnesium hydroxide per capsule. How many moles of aluminum hydroxide does each capsule contain? What is the mass in milligrams of 0.0734 moles of magnesium hydroxide?

## Molar Mass

Molar mass is widely used to quantitatively describe the mass of a specific substance, which defined as the mass of the sample in grams divided by the number of moles. The international unit for molar mass is g/mol.

## Answer and Explanation:

The molar mass of {eq}Al(OH)_3 {/eq} is 78 g/mol. For 200 mg of {eq}Al(OH)_3 {/eq} in the capsule, the mole is:

{eq}(200 \div 1000) \div 78 = \boxed{0.0026 \ mol} {/eq}

The molar mass of {eq}Mg(OH)_2 {/eq} is 58.32 g/mol. For 0.0734 moles, the mass is:

{eq}0.0734 \times 58.32 = 4.28 \ g = \boxed{4280 \ mg} {/eq}

#### Ask a question

Our experts can answer your tough homework and study questions.

Ask a question Ask a question#### Search Answers

#### Learn more about this topic:

from General Studies Science: Help & Review

Chapter 27 / Lesson 24