Step 1: Determine the molarity of the concentrated HCl solution.
The concentration of the concentrated HCl solution is given as 37% HCl. This means that 37 g of HCl is present in 100 g of the solution. The molar mass of HCl is 36.46 g/mol. Therefore, the molarity of the concentrated HCl solution can be calculated as follows:
Molarity (M) = (Mass of HCl in grams) / (Molar mass of HCl in g/mol) x (Volume of solution in liters)
Molarity (M) = (37 g) / (36.46 g/mol) x (100 mL / 1000 mL)
= 10.13 M
Step 2: Calculate the volume of concentrated HCl required.
To prepare 0.5M HCl, you need to dilute the concentrated HCl solution with water. The volume of concentrated HCl required can be calculated using the formula:
Volume of concentrated HCl (mL) = (Desired volume of solution in liters) x (Desired Molarity) / (Molarity of concentrated HCl)
Volume of concentrated HCl (mL) = (1 L) x (0.5 M) / (10.13 M)
= 0.049 L or 49.4 mL
Step 3: Prepare the 0.5M HCl solution.
In a fume hood, slowly add the calculated volume of concentrated HCl to a container containing distilled water. Be careful while handling concentrated HCl as it is corrosive. Always add acid to water, never water to acid. Stir the solution thoroughly to ensure uniform mixing.
Step 4: Adjust the volume to 1 liter.
Add additional distilled water to the solution until the final volume reaches 1 liter. Mix well to ensure complete homogeneity.
By following these steps, you can successfully prepare 0.5M HCl from 37% HCl. Always remember to wear appropriate personal protective equipment (PPE) while working with concentrated acids.
