Question

What volume of a concentrated HCL , which is 36.0% HCL by mass and has a density of 1.179g/mL , should be used to make 5.10 L of an HCL solution with a pH of 1.5

Answer 1

Concepts and reason

The concept used to solve this question is to calculate the volume of the concentrated HCl solution to make 5.10 L of HCl solution of pH = 1.5. The percentage and density of HCl solution is given. From the given pH value, the concentration of ions is calculated. From the concentration of, the weight of HCl is calculated. Using the density of HCl, the volume of concentrated HCl is calculated.

Fundamentals

1) Concentration of the solution can be calculated by the molarity equation which is defined as the number of moles of compound per liter of solution. This is also known as molar concentration.

2) pH: The pH of the solution can be defined as the negative logarithm of concentration of ions in the solution.

3) Density of any substance can be given by the following formula. It is a characteristic property of the substance.

The pH of the solution to be prepared = 1.5

The concentration of ion is calculated by substituting the pH in the following equation.

Therefore, the concentration of ion or HCl solution to be prepared = 0.0316 M.

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Therefore, the mass of HCl solution to be prepared = 5.87 g.

The mass of HCl solution to be prepared = 5.87 g.

But the given percentage of concentrated HCl is 36% by mass.

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The volume of the concentrated solution is calculated by substituting the mass and density of HCl solution in the following formula.

Therefore, the volume of concentrated HCl which is 36% by mass, is required to prepare 5.1 L of HCl solution of pH 1.5 = 13.83 mL.

Ans:

The volume of concentrated HCl solution required = 13.83 mL.