How to Calculate and Prepare a 5M Sodium Chloride Solution- A Step-by-Step Guide

How to Prepare 5M NaCl Calculation

Preparing a 5M (molar) solution of sodium chloride (NaCl) is a common task in chemistry and various other scientific fields. This solution is widely used in scientific experiments, medical applications, and food preservation. The process involves accurately calculating the amount of NaCl needed to dissolve in a specific volume of solvent, typically water. In this article, we will guide you through the steps to calculate and prepare a 5M NaCl solution.

Understanding Molarity

Before diving into the calculation, it is essential to understand the concept of molarity. Molarity (M) is defined as the number of moles of solute (in this case, NaCl) dissolved in one liter of solution. The formula for molarity is:

Molarity (M) = Moles of solute / Volume of solution (in liters)

In our case, we want to prepare a 5M NaCl solution, which means there will be 5 moles of NaCl dissolved in one liter of solution.

Calculating the Moles of NaCl

To calculate the moles of NaCl needed, you will need to know the molar mass of NaCl. The molar mass of NaCl is the sum of the atomic masses of sodium (Na) and chlorine (Cl), which are 22.99 g/mol and 35.45 g/mol, respectively. Adding these values gives us a molar mass of 58.44 g/mol for NaCl.

Now, let’s calculate the moles of NaCl needed for a 5M solution:

Moles of NaCl = Molarity (M) × Volume of solution (in liters)

Since we want a 5M solution, we can use the following formula:

Moles of NaCl = 5 M × 1 L = 5 moles

Calculating the Mass of NaCl

Now that we know we need 5 moles of NaCl, we can calculate the mass of NaCl required. To do this, we multiply the moles of NaCl by its molar mass:

Mass of NaCl = Moles of NaCl × Molar mass of NaCl

Mass of NaCl = 5 moles × 58.44 g/mol = 292.2 g

Therefore, you will need 292.2 grams of NaCl to prepare a 5M solution.

Preparation of the 5M NaCl Solution

To prepare the 5M NaCl solution, follow these steps:

1. Weigh out 292.2 grams of NaCl using a balance.
2. Pour approximately 500 mL of distilled water into a beaker.
3. Gradually add the NaCl to the water while stirring until it is completely dissolved.
4. Once the NaCl is dissolved, measure the total volume of the solution using a graduated cylinder or volumetric flask.
5. If the volume is less than 500 mL, add distilled water to reach the desired volume.
6. Stir the solution to ensure complete mixing.

Congratulations! You have now prepared a 5M NaCl solution. Remember to store it in a labeled container and use it as per the requirements of your experiment or application.