Preparation of 0.1 N H2SO4 Solution
Introduction
Hydrogen sulfate (H2SO4) is a strong acid commonly used in various laboratory applications, including titrations, chemical reactions, and cleaning purposes. In this article, we will discuss the preparation of a 0.1 normal (0.1 N) H2SO4 solution, which is a commonly used concentration in analytical chemistry.
Definition of Normality (N)
Normality (N) is a measure of the concentration of a solution in terms of the number of equivalents per liter. One equivalent is the amount of a substance that reacts with one mole of hydrogen ions (H+). For sulfuric acid (H2SO4), one equivalent is equal to one mole of H2SO4 divided by two, since each molecule of H2SO4 can donate two hydrogen ions.
Materials Needed
- Sulfuric acid (H2SO4) with a concentration of 98% (w/w)
- Distilled water
- A 1-liter volumetric flask
- A pipette or graduated cylinder
Preparation of 0.1 N H2SO4 Solution
To prepare a 0.1 N H2SO4 solution, you will need to dilute a small amount of concentrated H2SO4 with distilled water.
Step 1: Calculate the Volume of H2SO4 Needed
First, calculate the volume of 98% H2SO4 needed to prepare 1 liter of 0.1 N H2SO4 solution. The molarity of 98% H2SO4 is approximately 18 M. Since we want to prepare a 0.1 N solution, we need to calculate the volume of 18 M H2SO4 required to prepare 1 liter of 0.1 N solution.
Calculation:
Molarity of 98% H2SO4 = 18 M Normality of desired solution = 0.1 N Molecular weight of H2SO4 = 98.08 g/mol
Number of moles of H2SO4 required = Normality x Volume (L) = 0.1 x 1 = 0.1 mol Mass of H2SO4 required = Number of moles x Molecular weight = 0.1 x 98.08 = 9.808 g Volume of 98% H2SO4 required = Mass of H2SO4 required / Density of 98% H2SO4 = 9.808 g / 1.84 g/mL = 5.33 mL
Step 2: Prepare the Solution
Using a pipette or graduated cylinder, carefully measure out 5.33 mL of 98% H2SO4 into a 1-liter volumetric flask.
Caution: Handle concentrated H2SO4 with care, as it is highly corrosive and can cause severe burns.
Step 3: Dilute with Distilled Water
Slowly add distilled water to the volumetric flask while gently swirling the mixture. Continue adding water until the total volume reaches 1 liter.
Step 4: Mix and Label
Mix the solution well and label it as 0.1 N H2SO4 solution.
Tips and Precautions
- Always handle concentrated H2SO4 with care, wearing protective gloves, goggles, and a lab coat.
- Prepare the solution in a well-ventilated area, away from any sources of ignition.
- Store the 0.1 N H2SO4 solution in a tightly sealed container, away from direct sunlight and heat sources.
By following these steps, you can prepare a 0.1 N H2SO4 solution that is suitable for various laboratory applications.
