How to Safely Prepare 1M HCl Solution in Just 100 mL- A Step-by-Step Guide

How to Prepare 1M HCl in 100 mL

Preparing a 1M (molar) solution of hydrochloric acid (HCl) in a 100 mL volume is a common task in chemistry laboratories. This process requires careful measurement and mixing to ensure the accuracy of the concentration. Here’s a step-by-step guide on how to prepare 1M HCl in 100 mL.

Materials Needed:

Before starting, gather the following materials:

– 1M HCl stock solution (concentrated)
– Distilled water
– A 100 mL volumetric flask
– A graduated cylinder or pipette
– Safety equipment: gloves, goggles, and a lab coat

Step 1: Safety Precautions

Hydrochloric acid is a corrosive and hazardous substance. Always wear appropriate safety equipment, including gloves, goggles, and a lab coat, to protect yourself from potential exposure.

Step 2: Measuring the Concentrated HCl

Begin by measuring the required volume of the concentrated HCl stock solution. The concentration of the stock solution is typically 36.5% (w/w) or 11.7M. To prepare 1M HCl in 100 mL, you will need to dilute the stock solution. The formula for calculating the volume of stock solution needed is:

\[ \text{Volume of stock solution} = \frac{\text{Molarity of desired solution} \times \text{Volume of desired solution}}{\text{Molarity of stock solution}} \]

For 1M HCl in 100 mL, the calculation is:

\[ \text{Volume of stock solution} = \frac{1M \times 100mL}{11.7M} \approx 8.5mL \]

Use a graduated cylinder or pipette to measure 8.5 mL of the concentrated HCl.

Step 3: Diluting the Concentrated HCl

Pour the measured 8.5 mL of concentrated HCl into the 100 mL volumetric flask. Be cautious as the concentrated HCl will react with water, releasing heat. Add the HCl to the flask first, then slowly add distilled water to the flask while swirling gently to ensure proper mixing.

Step 4: Finalizing the Solution

Once the 8.5 mL of concentrated HCl is dissolved in the flask, continue adding distilled water to the flask until the solution reaches the 100 mL mark. Use the volumetric flask’s graduation line as a guide. Swirl the flask gently to mix the solution thoroughly.

Step 5: Safety and Storage

After preparing the 1M HCl solution, make sure to properly label the flask with the concentration and date. Store the solution in a cool, dry place, away from direct sunlight and incompatible materials. Always handle the solution with care and follow proper disposal procedures for any leftover or waste material.

By following these steps, you can successfully prepare a 1M HCl solution in 100 mL, ensuring the accuracy and safety of your chemistry experiments.