How do you prepare a 1 M HCl solution which has a specific gravity of 1.18? The HCl solution has 35% purity. Calculate the volume required to prepare the solution.

To prepare a 1 M hydrochloric acid (HCl) solution with a specific gravity of 1.18 and a purity of 35%, we need to follow a series of steps involving some calculations. Let’s break this down step by step.

Understanding Molarity and Purity

Molarity (M) is defined as the number of moles of solute per liter of solution. In this case, we want a 1 M solution of HCl, which means we need 1 mole of HCl in every liter of the solution. The purity of the HCl solution indicates that only 35% of the solution is pure HCl, while the rest is water and other components.

Calculating the Required Amount of HCl

First, we need to determine how many grams of HCl are required to achieve 1 mole. The molar mass of HCl is approximately 36.46 g/mol. Therefore, for a 1 M solution, we need:

• 1 mole of HCl = 36.46 grams of HCl

Adjusting for Purity

Since the HCl solution is only 35% pure, we need to calculate the total mass of the solution required to obtain 36.46 grams of pure HCl. We can use the formula:

• Mass of solution = Mass of pure HCl / Purity

Substituting the values:

• Mass of solution = 36.46 g / 0.35 ≈ 104.17 g

Using Specific Gravity to Find Volume

Next, we can use the specific gravity to find the volume of the solution needed. Specific gravity is the ratio of the density of a substance to the density of water. Since the specific gravity of our HCl solution is 1.18, we can calculate the density:

• Density = Specific Gravity × Density of water = 1.18 g/mL × 1 g/mL = 1.18 g/mL

Now, we can find the volume of the solution required using the formula:

• Volume = Mass / Density

Substituting the values we have:

• Volume = 104.17 g / 1.18 g/mL ≈ 88.4 mL

Final Steps

To prepare the 1 M HCl solution, you would need to measure out approximately 88.4 mL of the 35% HCl solution. Then, dilute this volume with distilled water to reach a final volume of 1 liter. Always remember to add acid to water, not the other way around, to ensure safety during the mixing process.

In summary, to prepare a 1 M HCl solution with a specific gravity of 1.18 and 35% purity, you will need about 88.4 mL of the concentrated HCl solution, which you will then dilute to a total volume of 1 liter. This method ensures that you achieve the desired molarity while accounting for the purity and density of the solution.