Question

What is the pH and pOH of a 2.2 x 10^-3 HBr solution?

Answer 1

Answer:

The pH and pOH of a 2.2*10⁻³ HBr solution is 2.66 and 11.34  respectively.

Explanation:

pH - short for hydrogen potential - is a measure of the acidity or alkalinity of a solution. So the pH is a parameter that indicates the concentration of hydrogen ions [H]⁺ that exist in a solution.

The pH is expressed as the negative base 10 logarithm of the hydrogen ion concentration. This is represented by:

pH= - log [H⁺]

pH is measured on a scale of 0 to 14. On this scale, a pH value of 7 is neutral, which means that the substance or solution is neither acidic nor alkaline. A pH value of less than 7 means that it is more acidic, and a pH value of more than 7 means that it is more alkaline.

HBr is a strong acid. Then, in aqueous solution it will be  totally dissociated. So the proton concentration is equal to the initial concentration of  acid:

[H⁺]= [HBr]= 2.2*10⁻³ M

So:

pH= - log (2.2*10⁻³)

pH= 2.66

On the other hand, pOH is a measure of the concentration of hydroxyl ions in a solution. The sum of pH and pOH equals 14:

pH + pOH= 14

2.66 + pOH= 14

pOH= 14 - 2.66

pOH= 11.34

The pH and pOH of a 2.2*10⁻³ HBr solution is 2.66 and 11.34  respectively.