Question

What is the ph of a solution for which [OH-] = 3.0 x 10-8

(a) 6.48
(b) 7.52
(c) 8.00
(d) 5.52

Answer 1

`\huge{ \boxed{6.48}}`

Step-by-step explanation:

The pH given the concentration of the OH ions can be found by using the formula:

pH + pOH = 14

To find pOH of the solution we use the formula:

`\bold{pOH = -log([{OH}^(-)])}`

From the question:

`[{OH}^(-)] = 3.0 * {10}^(-8) \: M`

`\therefore pOH = -log(3.0 * {10}^(-8)) \\ = 7.523`

`\therefore \: pH = 14 - 7 .523 \\ = 6.477 \approx6.48`

Answer 2

The pH of the solution with [OH-] = 3.0 x 10^-8 is approximately 6.48, which indicates that the solution is slightly acidic as it is less than 7 but very close to being neutral.

Step-by-step explanation:

The pH of a solution is calculated using the hydrogen ion concentration ([H+]), which is related to the hydroxide ion concentration ([OH-]) through the water dissociation constant (Kw = 1.0 x 10-14 at 25°C). Given that [OH-] = 3.0 x 10-8, we first need to find [H+] using the equation Kw = [H+][OH-].

Calculating [H+]:
[H+] = Kw / [OH-] = 1.0 x 10-14 / 3.0 x 10-8 = 3.33 x 10-7

Now to find the pH:
pH = -log[H+] = -log(3.33 x 10-7) ≈ 6.48

This pH value indicates that the solution is slightly acidic, as pH less than 7 is considered acidic. However, since the pH is very close to neutral (pH = 7), the solution is very weakly acidic.