Molar Mass of Calcium Hydroxide

Oct 13, 2025 by wbrum.org 8 views

Introduction

In this article, we will explore the chemical reaction between calcium hydroxide and water, and calculate the number of molecules of calcium hydroxide produced when 35.0 grams of water is used. This reaction is a fundamental concept in chemistry, and understanding it is crucial for various applications in fields such as environmental science, materials science, and pharmaceuticals.

Chemical Reaction

The chemical reaction between calcium hydroxide (Ca(OH)2) and water (H2O) is as follows:

Ca(OH)2 + 2H2O → Ca(OH)2·2H2O

In this reaction, calcium hydroxide reacts with water to form a hydrated calcium hydroxide complex. The reaction is a simple example of a chemical reaction between a solid and a liquid.

Molar Mass of Water

To calculate the number of molecules of calcium hydroxide produced, we need to know the molar mass of water. The molar mass of water is 18.02 grams per mole (g/mol).

Molar Mass of Calcium Hydroxide

The molar mass of calcium hydroxide is 74.09 g/mol.

Limiting Reactant

In this reaction, calcium hydroxide is the limiting reactant, meaning that it is the reactant that is present in the smallest amount. Water is the excess reactant.

Stoichiometry

To calculate the number of molecules of calcium hydroxide produced, we need to use the stoichiometry of the reaction. The balanced chemical equation shows that 1 mole of calcium hydroxide reacts with 2 moles of water to produce 1 mole of hydrated calcium hydroxide complex.

Calculation

To calculate the number of molecules of calcium hydroxide produced, we need to follow these steps:

Calculate the number of moles of water used.
Calculate the number of moles of calcium hydroxide produced.
Calculate the number of molecules of calcium hydroxide produced.

Step 1: Calculate the number of moles of water used

To calculate the number of moles of water used, we need to divide the mass of water used (35.0 grams) by the molar mass of water (18.02 g/mol).

moles of water = mass of water / molar mass of water moles of water = 35.0 g / 18.02 g/mol moles of water = 1.94 mol

Step 2: Calculate the number of moles of calcium hydroxide produced

Since the stoichiometry of the reaction shows that 1 mole of calcium hydroxide reacts with 2 moles of water, we can calculate the number of moles of calcium hydroxide produced by dividing the number of moles of water used by 2.

moles of calcium hydroxide = moles of water / 2 moles of calcium hydroxide = 1.94 mol / 2 moles of calcium hydroxide = 0.97 mol

Step 3: Calculate the number of molecules of calcium hydroxide produced

To calculate the number of molecules of calcium hydroxide produced, we need to multiply the number of moles of calcium hydroxide produced by Avogadro's number (6.022 x 10^23 molecules per mole).

number of molecules of calcium hydroxide = moles of calcium hydroxide x Avogadro's number number of molecules of calcium hydroxide = 0.97 mol x 6.022 x 10^23 molecules/mol number of molecules of calcium hydroxide = 5.83 x 10^22 molecules

Conclusion

In conclusion, when 35.0 grams of water is used in the reaction between calcium hydroxide and water, 5.83 x 10^22 molecules of calcium hydroxide are produced. This calculation demonstrates the importance of understanding stoichiometry and chemical reactions in chemistry.

References

"Chemical Reactions and Stoichiometry" by OpenStax
"Chemistry: The Central Science" by Theodore L. Brown, H. Eugene LeMay, Jr., and Bruce E. Bursten

FAQs

Q: What is the chemical reaction between calcium hydroxide and water? A: The chemical reaction between calcium hydroxide and water is Ca(OH)2 + 2H2O → Ca(OH)2·2H2O.
Q: What is the molar mass of water? A: The molar mass of water is 18.02 g/mol.
Q: What is the molar mass of calcium hydroxide? A: The molar mass of calcium hydroxide is 74.09 g/mol.
Q: What is the stoichiometry of the reaction? A: The stoichiometry of the reaction shows that 1 mole of calcium hydroxide reacts with 2 moles of water to produce 1 mole of hydrated calcium hydroxide complex.

Introduction

In our previous article, we explored the chemical reaction between calcium hydroxide and water, and calculated the number of molecules of calcium hydroxide produced when 35.0 grams of water is used. In this article, we will answer some frequently asked questions (FAQs) related to this topic.

Q&A

Q: What is the chemical reaction between calcium hydroxide and water?

A: The chemical reaction between calcium hydroxide and water is Ca(OH)2 + 2H2O → Ca(OH)2·2H2O.

Q: What is the molar mass of water?

A: The molar mass of water is 18.02 g/mol.

Q: What is the molar mass of calcium hydroxide?

A: The molar mass of calcium hydroxide is 74.09 g/mol.

Q: What is the stoichiometry of the reaction?

A: The stoichiometry of the reaction shows that 1 mole of calcium hydroxide reacts with 2 moles of water to produce 1 mole of hydrated calcium hydroxide complex.

Q: How many moles of water are used in the reaction?

A: To calculate the number of moles of water used, we need to divide the mass of water used (35.0 grams) by the molar mass of water (18.02 g/mol).

moles of water = mass of water / molar mass of water moles of water = 35.0 g / 18.02 g/mol moles of water = 1.94 mol

Q: How many moles of calcium hydroxide are produced in the reaction?

A: Since the stoichiometry of the reaction shows that 1 mole of calcium hydroxide reacts with 2 moles of water, we can calculate the number of moles of calcium hydroxide produced by dividing the number of moles of water used by 2.

moles of calcium hydroxide = moles of water / 2 moles of calcium hydroxide = 1.94 mol / 2 moles of calcium hydroxide = 0.97 mol

Q: How many molecules of calcium hydroxide are produced in the reaction?

A: To calculate the number of molecules of calcium hydroxide produced, we need to multiply the number of moles of calcium hydroxide produced by Avogadro's number (6.022 x 10^23 molecules per mole).

Q: What is the significance of this reaction?

A: This reaction is a fundamental concept in chemistry, and understanding it is crucial for various applications in fields such as environmental science, materials science, and pharmaceuticals.

Q: What are some real-world applications of this reaction?

A: Some real-world applications of this reaction include:

Water treatment: Calcium hydroxide is used to remove impurities from water.
Construction: Calcium hydroxide is used as a binding agent in concrete.
Pharmaceuticals: Calcium hydroxide is used as an excipient in some pharmaceutical formulations.

Conclusion

In conclusion, the chemical reaction between calcium hydroxide and water is a fundamental concept in chemistry, and understanding it is crucial for various applications in fields such as environmental science, materials science, and pharmaceuticals. We hope that this Q&A article has provided you with a better understanding of this topic.

References

"Chemical Reactions and Stoichiometry" by OpenStax
"Chemistry: The Central Science" by Theodore L. Brown, H. Eugene LeMay, Jr., and Bruce E. Bursten

FAQs

Q: What is the chemical reaction between calcium hydroxide and water? A: The chemical reaction between calcium hydroxide and water is Ca(OH)2 + 2H2O → Ca(OH)2·2H2O.
Q: What is the molar mass of water? A: The molar mass of water is 18.02 g/mol.
Q: What is the molar mass of calcium hydroxide? A: The molar mass of calcium hydroxide is 74.09 g/mol.
Q: What is the stoichiometry of the reaction? A: The stoichiometry of the reaction shows that 1 mole of calcium hydroxide reacts with 2 moles of water to produce 1 mole of hydrated calcium hydroxide complex.