Given Information and Objectives

Oct 13, 2025 by wbrum.org 21 views

Understanding the Chemical Reaction

In this article, we will delve into the world of chemistry and explore a specific chemical reaction involving sodium chloride (NaCl), calcium hydroxide (Ca(OH)2), and sodium hydroxide (NaOH). The reaction is as follows:

${2 \, \text{NaCl} + \text{Ca(OH)}_2 \rightarrow \text{CaCl}_2 + 2 \, \text{NaOH}}$

This reaction is a classic example of a double displacement reaction, where two compounds exchange partners to form two new compounds.

Given Information and Objectives

We are given the following information:

191.0 grams of sodium chloride (NaCl) reacts with 74.0 grams of calcium hydroxide (Ca(OH)2).
80 grams of sodium hydroxide (NaOH) is produced.

Our objective is to determine the mass of calcium chloride (CaCl2) produced in this reaction.

Balancing the Chemical Equation

Before we proceed with the mass calculations, let's balance the chemical equation to ensure that the number of atoms of each element is the same on both the reactant and product sides.

The balanced equation is:

${2 \, \text{NaCl} + \text{Ca(OH)}_2 \rightarrow \text{CaCl}_2 + 2 \, \text{NaOH}}$

Calculating the Number of Moles of Reactants

To calculate the mass of calcium chloride produced, we need to calculate the number of moles of each reactant.

The molar masses of the reactants are:

NaCl: 58.44 g/mol
Ca(OH)2: 74.09 g/mol

Using the given masses, we can calculate the number of moles of each reactant:

${ \text{moles of NaCl} = \frac{191.0 \, \text{g}}{58.44 \, \text{g/mol}} = 3.25 \, \text{mol} }$

${ \text{moles of Ca(OH)}_2 = \frac{74.0 \, \text{g}}{74.09 \, \text{g/mol}} = 1.00 \, \text{mol} }$

Calculating the Number of Moles of Products

Since the balanced equation shows a 1:1 ratio between Ca(OH)2 and CaCl2, we can calculate the number of moles of CaCl2 produced:

${ \text{moles of CaCl}_2 = \text{moles of Ca(OH)}_2 = 1.00 \, \text{mol} }$

Calculating the Mass of Calcium Chloride Produced

Now that we have the number of moles of CaCl2, we can calculate its mass using its molar mass:

${ \text{molar mass of CaCl}_2 = 110.98 \, \text{g/mol} }$

${ \text{mass of CaCl}_2 = \text{moles of CaCl}_2 \times \text{molar mass of CaCl}_2 }$

${ \text{mass of CaCl}_2 = 1.00 \, \text{mol} \times 110.98 \, \text{g/mol} = 110.98 \, \text{g} }$

Conclusion

In this article, we have walked through the steps of balancing a chemical equation and calculating the mass of a product using the given masses of reactants. We have seen how to calculate the number of moles of each reactant and product, and how to use the molar masses to calculate the mass of the product.

The final answer is: 110.98 grams

Q: What is the purpose of balancing a chemical equation?

A: Balancing a chemical equation is essential to ensure that the number of atoms of each element is the same on both the reactant and product sides. This is crucial in understanding the stoichiometry of a reaction and predicting the amounts of products formed.

Q: How do I balance a chemical equation?

A: To balance a chemical equation, follow these steps:

Write the unbalanced equation.
Count the number of atoms of each element on both the reactant and product sides.
Add coefficients (numbers in front of formulas) to balance the equation.
Check that the number of atoms of each element is the same on both sides.

Q: What is the difference between a balanced and unbalanced equation?

A: A balanced equation has the same number of atoms of each element on both the reactant and product sides. An unbalanced equation does not have the same number of atoms of each element on both sides.

Q: How do I calculate the number of moles of a substance?

A: To calculate the number of moles of a substance, use the formula:

moles = mass / molar mass

Where mass is the given mass of the substance and molar mass is the mass of one mole of the substance.

Q: What is the molar mass of a substance?

A: The molar mass of a substance is the mass of one mole of the substance. It is calculated by adding the atomic masses of all the atoms in the substance.

Q: How do I calculate the mass of a product using the number of moles and molar mass?

A: To calculate the mass of a product, use the formula:

mass = moles x molar mass

Where moles is the number of moles of the product and molar mass is the mass of one mole of the product.

Q: What is the significance of the balanced equation in this article?

A: The balanced equation is crucial in understanding the stoichiometry of the reaction and predicting the amounts of products formed. It helps us to calculate the number of moles of each reactant and product, and ultimately, the mass of the product.

Q: Can I use the balanced equation to predict the amounts of products formed in a reaction?

A: Yes, the balanced equation can be used to predict the amounts of products formed in a reaction. By knowing the number of moles of each reactant and the coefficients in the balanced equation, we can calculate the number of moles of each product and ultimately, the mass of the product.

Q: What are some common mistakes to avoid when balancing a chemical equation?

A: Some common mistakes to avoid when balancing a chemical equation include:

Not counting the number of atoms of each element on both sides.
Adding coefficients without checking that the number of atoms of each element is the same on both sides.
Not checking that the number of atoms of each element is the same on both sides after adding coefficients.

Q: How do I know if a chemical equation is balanced?

A: A chemical equation is balanced if the number of atoms of each element is the same on both the reactant and product sides. You can check this by counting the number of atoms of each element on both sides and making sure they are equal.

Q: Can I use the balanced equation to predict the amounts of reactants required in a reaction?

A: Yes, the balanced equation can be used to predict the amounts of reactants required in a reaction. By knowing the number of moles of each product and the coefficients in the balanced equation, we can calculate the number of moles of each reactant and ultimately, the mass of the reactant.

Q: What are some real-world applications of balancing chemical equations and mass calculations?

A: Some real-world applications of balancing chemical equations and mass calculations include:

Predicting the amounts of products formed in a reaction.
Calculating the amounts of reactants required in a reaction.
Understanding the stoichiometry of a reaction.
Designing and optimizing chemical processes.
Predicting the environmental impact of a reaction.