What is the pH of a solution that is formed at 25C by combin

What is the pH of a solution that is formed at 25C by combining 300 mL of 0.040 M NaOH with 400 mL of 0.030 M HCl?

Solution

The amount of OH- ions released by NaOH is 0.04*300.
The amount of H+ ions released by HCl is 0.03*400

So the amount of H+ by HCl and amount of OH- by NaOH cancel each other.

This inturn makes the water neutral and the

pH remains 7.

pH = 7