Q: Which equation correctly expresses the relationship between $$[H^+]$$ and $$[OH^-] in $$water at 25°C?

$$[H^+] \times [OH^-] = 10$$^{-14}$$

Question 1

At 25°C, the product of the molar concentrations of $$[H^+]$$ and $$[OH^-] in $$any aqueous solution is a constant. What is the value of this constant?

Accepted Answer

$$10^{-14}$$

Question 2

In a neutral solution at 25°C, what are the molar concentrations of $$[H^+]$$ and $$[OH^-]$$?

Accepted Answer

$$[H^+] = 10$$^{-7}$$ \ M$$, $$[OH^-] = 10$$^{-7}$$ \ M$$

Question 3

If enough acid is added to an aqueous solution at 25°C to increase $$[H^+] to$$ $$10^{-5}$$ \ M$$, what will be the new $$[OH^-]$$ concentration?

Accepted Answer

$$10^{-9}$$ \ M$$

Question 4

Which equation correctly expresses the relationship between $$[H^+]$$ and $$[OH^-] in $$water at 25°C?

Accepted Answer

$$[H^+] 	imes [OH^-] = 10$$^{-14}$$

Question 5

A base is added to an aqueous solution, raising the $$[OH^-]$$ concentration to $$10^{-4}$$ \ M$$. What is the resulting $$[H^+]$$ concentration?

Accepted Answer

$$10^{-10}$$ \ M$$

Question 6

If the $$[H^+] in a $$solution is $$10^{-3}$$ \ M$$, what is the pH of the solution?

Accepted Answer

pH = 3

Question 7

Which of the following best describes the effect of adding a strong acid to pure water at 25°C?

Accepted Answer

The $$[H^+]$$ increases and $$[OH^-]$$ decreases.

Question 8

If a solution at 25°C has $$[OH^-] = 10$$^{-6}$$ \ M$$, what is the $$[H^+]$$?

Accepted Answer

$$10^{-8}$$ \ M$$

Question 9

Which of the following statements about the ion product constant for water ($$K_w) at 25$$°C is correct?

Accepted Answer

$$K_w = [H^+][OH^-] = 10$$^{-14}$$ at 25°C.

Question 10

A solution has $$[H^+] = 10$$^{-9}$$ \ M at 25$$°C. What is the $$[OH^-]$$?

Accepted Answer

$$10^{-5}$$ \ M$$

Question 11

Which of the following best explains why $$[H^+]$$ and $$[OH^-]$$ are inversely related in aqueous solutions at 25°C?

Accepted Answer

Because their product must always equal $$10^{-14}.$$

Question 12

If a solution is neutral at 25°C, what is its pH?

Accepted Answer

pH = 7

Question 13

A solution has $$[OH^-] = 10$$^{-3}$$ \ M at 25$$°C. What is the pOH of the solution?

Accepted Answer

pOH = 3

Question 14

If $$[H^+] in a $$solution is $$10^{-8}$$ \ M$$, what is the pH and is the solution acidic, basic, or neutral?

Accepted Answer

pH = 8, basic

Question 15

Which of the following best describes what happens to $$[H^+] if$$ $$[OH^-] is $$increased to $$10^{-2}$$ \ M$$ at 25°C?

Accepted Answer

$$[H^+]$$ decreases to $$10^{-12}$$ \ M$$

The pH Scale and the Chemical Context of Life

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