. Calculate the hydrogen ion concentration and the pH of each of the following solutions of strong acids.

a. 1.04 × 10 − 4 M HCI

b. 0.00301 M HNO

c. 5.41 × 10 − 4 M HClO₄

d. 6.42 × 1 0 − 2 M HNO₃

(a)

Interpretation:

The pH and hydrogen ion concentration of a solution of 1.04×10−4 M

HCl should be calculated.

Concept Introduction:

To express the small number, p scale is used, which implies to take the log of a number. Since, the concentration of [H+] in aqueous solution is small, by using the p scale in the form of pH scale, it is better way to represent acidity of solution.

Thus, pH = -log [H+].

Since, HCl is a strong acid, thus it is completely dissociated into ions. The reaction is shown below:

HCl→H++Cl−

Thus, concentration of HCl that is 1.04×10−4 M is equal to the [H+] and [Cl-]

Therefore, [H+] = 1

(b)

Interpretation:

The pH and hydrogen ion concentration of a solution of 0.00301 M

HNO3 should be calculated.

Concept Introduction:

To express the small number, p scale is used, which implies to take the log of a number. Since, the concentration of [H+] in aqueous solution is small, by using the p scale in the form of pH scale, it is better way to represent acidity of solution.

Thus, pH = -log [H+].

(c)

Interpretation:

The pH and hydrogen ion concentration of a solution of 5.41×10−4 M

HClO4 should be calculated.

Concept Introduction:

To express the small number, p scale is used, which implies to take the log of a number. Since, the concentration of [H+] in aqueous solution is small, by using the p scale in the form of pH scale, it is better way to represent acidity of solution.

Thus, pH = -log [H+].

(d)

Interpretation:

The pH and hydrogen ion concentration of a solution of 6.42×10−2 M

HNO3 should be calculated.

Concept Introduction:

To express the small number, p scale is used, which implies to take the log of a number. Since, the concentration of [H+] in aqueous solution is small, by using the p scale in the form of pH scale, it is better way to represent acidity of solution.

Thus, pH = -log [H+].