0.1 N Sodium Hydroxide Solution Preparation
Introduction
Sodium hydroxide (NaOH) is a strong base commonly used in various laboratory applications. A 0.1 N (normal) sodium hydroxide solution is a standardized solution that is frequently used as a titrant in acid-base titrations, such as in the determination of acidity in food and pharmaceutical products. In this article, we will discuss the preparation of a 0.1 N sodium hydroxide solution.
Materials Needed
- Sodium hydroxide pellets (NaOH)
- Distilled water
- A weighing balance
- A 1000 mL volumetric flask
- A stirring rod
Preparation of 0.1 N Sodium Hydroxide Solution
To prepare a 0.1 N sodium hydroxide solution, you will need to dissolve a specific amount of sodium hydroxide pellets in distilled water. The following steps should be followed:
Step 1: Calculate the Amount of Sodium Hydroxide Pellets Needed
The normality of a solution is defined as the number of equivalents per liter of solution. Since we want to prepare a 0.1 N sodium hydroxide solution, we need to calculate the amount of sodium hydroxide pellets required to prepare 1000 mL (1 liter) of the solution.
The molecular weight of sodium hydroxide is 40 g/mol. The equivalent weight of sodium hydroxide is 40 g/equivalent. Therefore, the weight of sodium hydroxide required to prepare 1 liter of 0.1 N solution is:
Weight of NaOH = (Normality x Equivalent weight) / 1000 = (0.1 x 40) / 1000 = 4 g
Step 2: Weigh the Sodium Hydroxide Pellets
Using a weighing balance, weigh out 4 g of sodium hydroxide pellets.
Step 3: Dissolve the Sodium Hydroxide Pellets in Distilled Water
Place the weighed sodium hydroxide pellets in a 1000 mL volumetric flask. Add a small amount of distilled water to the flask and swirl it gently to dissolve the pellets. Once the pellets have dissolved, add more distilled water to the flask until it is about 3/4 full.
Step 4: Mix and Dilute the Solution
Use a stirring rod to mix the solution thoroughly. Then, add more distilled water to the flask until it reaches the 1000 mL mark.
Step 5: Mix Again and Label the Solution
Mix the solution again to ensure that it is homogeneous. Label the flask with the solution's concentration (0.1 N NaOH) and the date of preparation.
Precautions
When handling sodium hydroxide, it is essential to take necessary precautions to avoid accidents. Sodium hydroxide is a strong base that can cause severe burns, eye damage, and respiratory problems. Therefore, it is crucial to wear protective gloves, goggles, and a lab coat when handling the substance. Additionally, work in a well-ventilated area, and avoid inhaling the powder or the mist.
Storage
The prepared 0.1 N sodium hydroxide solution should be stored in a tightly closed container in a cool place, away from direct sunlight. The solution can be used for several months if stored properly. However, it is recommended to prepare a fresh solution regularly to ensure accurate results.
By following these steps and taking necessary precautions, you can successfully prepare a 0.1 N sodium hydroxide solution for your laboratory needs.
