Question

A solution has [H⁺]= 1 x 10⁻⁵ and [OH⁻] = 1 x 10⁻⁹ M. What is the pH and pOH?

A. pH= 5, pOH= 9
B. pH= 0, pOH= 5
C. pH= 9, pOH= 5
D. pH= 5, pOH= 0

Answer 1

A solution with [H+] = 1 x 10−5 and [OH−] = 1 x 10−9 has a pH of 5 and a pOH of 9, adhering to the relationship pH + pOH = 14.

Step-by-step explanation:

The question is asking us to calculate the pH and pOH of a solution with given concentrations of hydrogen ions [H+] and hydroxide ions [OH−]. We use the formulas pH = -log[H+] and pOH = -log[OH−]. Given [H+] = 1 x 10−5, the pH equals -log(1 x 10−5) which is 5. Similarly, with [OH−] = 1 x 10−9, the pOH equals -log(1 x 10−9) which is 9. Using the relationship that pH + pOH = 14, we can validate these answers. Therefore, the correct answer is A. pH = 5, pOH = 9.