How to Prepare 1 M HCl from 37% HCl Solution
Preparing a 1 M (molar) solution of hydrochloric acid (HCl) from a 37% HCl solution requires careful measurement and dilution. It is important to follow the correct procedure to ensure safety and accuracy. Here’s a step-by-step guide on how to prepare 1 M HCl from 37% HCl solution.
Step 1: Gather the Necessary Materials
Before you begin, make sure you have the following materials:
– 37% HCl solution
– Distilled water
– Measuring cylinder or graduated cylinder
– Safety equipment (gloves, goggles, lab coat)
– Beaker or flask
– Stirrer or magnetic stirrer
– Safety shower and eyewash station
Step 2: Calculate the Volume of 37% HCl Solution Needed
To prepare 1 liter of 1 M HCl, you need to dilute 37% HCl solution to the desired concentration. The molarity (M) is calculated using the formula:
M = (mass of solute / molar mass of solute) / volume of solution (in liters)
The molar mass of HCl is approximately 36.46 g/mol. To prepare 1 M HCl, you need 36.46 g of HCl in 1 liter of solution. Since the density of 37% HCl is approximately 1.19 g/mL, you can calculate the volume of 37% HCl solution needed using the following formula:
Volume (in mL) = (mass of HCl / density of 37% HCl) 100
For 1 M HCl, you need:
Volume (in mL) = (36.46 g / 1.19 g/mL) 100 ≈ 30.5 mL
Step 3: Prepare the Solution
1. Wear your safety equipment (gloves, goggles, lab coat) before starting the process.
2. Measure 30.5 mL of 37% HCl solution using a measuring cylinder or graduated cylinder.
3. Pour the measured 37% HCl solution into a beaker or flask.
4. Add distilled water to the beaker or flask, ensuring that the total volume reaches 1 liter.
5. Stir the solution gently with a stirrer or magnetic stirrer to mix the HCl and water thoroughly.
Step 4: Safety Precautions
– Always handle concentrated HCl with extreme caution. Use safety equipment, such as gloves and goggles, to protect yourself from exposure.
– Never add water to concentrated HCl; always add HCl to water to prevent a violent reaction.
– If you accidentally spill HCl on your skin or in your eyes, immediately rinse with water and seek medical attention if necessary.
– Ensure that you have a safety shower and eyewash station nearby in case of an emergency.
Step 5: Quality Control
After preparing the 1 M HCl solution, it is important to check its concentration using a pH meter or titration. If the concentration is not as expected, you may need to adjust the solution by adding more 37% HCl or distilled water.
By following these steps, you can successfully prepare 1 M HCl from a 37% HCl solution while ensuring your safety and the accuracy of the final product.
