29 November, 13:43

# What is the pH of a solution with [OH - ] = 1.60x10-9 M? Include two digits past the decimal in your answer.What is the pH of a solution if [H3O+] = 2.00x10-5 M? Include two digits past the decimal in your answer.A solution has a pH value of 3.90. What is the pOH for the solution? Include one digit past the decimal in your answer.

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1. 29 November, 16:21
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1) pH = 5.20

2) pH = 4.70

3) pOH = 10.1

Explanation:

What is the pH of a solution with [OH - ] = 1.60x10-9 M?

Step 1: Data given

[OH-] = 1.60 * 10^-9 M

Step 2: Calculate pOH

pOH = - log[OH-]

pOH = - log [1.60*10^-9]

pOH = 8.80

Step 3: Calculate pH

pH = 14 - pOH

pH = 14 - 8.8 = 5.20

What is the pH of a solution if [H3O+] = 2.00x10-5 M?

[H3O+] = [H+] = 2.00 * 10^-5 M

pH = - log[H+]

pH = - log[2.00*10^-5]

pH = 4.70

A solution has a pH value of 3.90. What is the pOH for the solution?

pOH = 14 - pH

pOH = 14 - 3.90 = 10.1
2. 29 November, 17:27
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Answer: 5.21, 4.69 & 10.1

Explanation:

Question 1:

We have to determine the pOH of the solution first.

pOH = - Log [OH-]

= - Log (1.60 x 10∧-9)

= 9 - 0.204

= 8.79

Using the mathematical equation;

pH + pOH = 14

∴ pH + 8.79 = 14

Making pH subject of formular; pH = 14 - 8.79 = 5.21

Question 2:

pH = - Log [H3O+]

= - Log (2.00 x 10∧-5)

= 5 - 0.301

= 4.69

Question 3:

Using the mathematical equation, pH + pOH = 14

3.90 + pOH = 14

∴ pOH = 14 - 3.90

= 10.1