1. What is the pH of a solution if the [OH-] = 4.0x10-11M?

pH = 4

Explanation:

Given data

[OH⁻] = 4.0 * 10⁻¹¹ M

Step 1: Calculate the pOH

We will use the following expression.

pOH = - log [OH⁻]

pOH = - log 4.0 * 10⁻¹¹

pOH = 10

Step 2: Calculate the pH

We will use the following expression.

pH + pOH = 14

pH = 14 - pOH

pH = 14 - 10

pH = 4

The pH scale is used to define the acidity or alkalinity of a solution. in this case, since pH < 4, the solution is acid.