To find pH of hydrochloric acid.
Lab data: on the attached file
Acid used to titrate 25.0mL of 0.150M potassium hydroxide.

1.22

Explanation:

Step 1:

We'll begin by writing the balanced equation for the reaction. This is given below:

HCl + KOH —> KCl + H2O

From the balanced equation above,

The mole ratio of acid (nA) = 1

The mole ratio of base (nB) = 1

Step 2:

Data obtained from the question. This includes the following:

Volume of acid (Va) =

(62.35 + 62.40)/2 = 62.38 mL

Molarity of acid (Ma) =.?

Volume of base (Vb) = 25 mL

Molarity of base (Mb) = 0.150M

Step 3:

Determination of the molarity of the acid.

This is illustrated below:

MaVa/MbVb = nA/nB

Ma x 62.38/ 0.15 x 25 = 1

Cross multiply to express in linear form

Ma x 62.38 = 0.15 x 25

Divide both side by 62.38

Ma = (0.15 x 25) /62.38

Ma = 0.06M

The molarity of the acid is 0.06M

Step 4:

Determination of the concentration of Hydrogen ion, [H+] in the acid. This is illustrated below:

Hydrochloric acid (HCl) will dissociate to produce hydrogen ion as follow:

HCl —> H+ + Cl-

From the above equation,

1 mole of HCl produced 1mole of H+.

Therefore, 0.06M HCl will also produce 0.06M H+.

The concentration of Hydrogen ion, [H+] is 0.06M

Step 5:

Determination of the pH of HCl. This is illustrated below:

pH = – Log [H+]

[H+] = 0.06M

pH = – Log 0.06

pH = 1.22

Therefore, the pH of HCl is 1.22