Q: A solution has a pH of 4. What is the $$[H^+]$$ concentration in this solution?

$$[H^+] = 1 \times 10$$^{-4}$$\ \mathrm{mol/L}$$

Q: Which of the following is a correct calculation for the pOH of a solution with $$[OH^-] = 2.0 \times 10$$^{-5}$$\ \mathrm{mol/L}$$?

$$pOH = -\log(2.0 \times 10$$^{-5}$$)$$

Q: A solution has a pH of 8.5. Which of the following is closest to its $$[H^+]$$ concentration?

$$[H^+] = 3.2 \times 10$$^{-9}$$\ \mathrm{mol/L}$$

Question 1

Which of the following statements best explains why a 0.10 mol/L solution of HCl has a lower pH than a 0.10 mol/L solution of CH₃COOH?

Accepted Answer

HCl is a strong acid and ionizes completely, producing more $$[H^+]$$ ions.

Question 2

A solution has a pH of 4. What is the $$[H^+]$$ concentration in this solution?

Accepted Answer

$$[H^+] = 1 	imes 10$$^{-4}$$\ \mathrm{mol/L}$$

Question 3

If the pH of a solution changes from 6 to 3, how does the $$[H^+]$$ concentration change?

Accepted Answer

It increases by a factor of 1000.

Question 4

Which of the following is a correct calculation for the pOH of a solution with $$[OH^-] = 2.0 	imes 10$$^{-5}$$\ \mathrm{mol/L}$$?

Accepted Answer

$$pOH = -\log(2.0 	imes 10$$^{-5}$$)$$

Question 5

A student mixes 50 mL of 0.10 mol/L HCl with 50 mL of 0.10 mol/L NaOH. What is the pH of the resulting solution?

Accepted Answer

pH = 7

Question 6

Which indicator would be most appropriate to detect the endpoint of a strong acid–strong base titration?

Accepted Answer

Phenolphthalein

Question 7

A solution has a pOH of 5. What is its pH at 25°C?

Accepted Answer

$$pH = 9$$

Question 8

Which of the following best describes the neutralization reaction between HNO₃ and KOH?

Accepted Answer

$$\mathrm{$$HNO_3$$} + \mathrm{KOH} \rightarrow \mathrm{$$KNO_3$$} + \mathrm{H_2O}$$

Question 9

A 0.0010 mol/L solution of HCl has a pH of 3.00. What would be the pH of a 0.0010 mol/L solution of acetic acid (CH₃COOH)?

Accepted Answer

Greater than 3.00

Question 10

Which of the following statements about strong acids is correct?

Accepted Answer

They dissociate completely in water, producing a high concentration of $$[H^+].$$

Question 11

If a solution has $$[OH^-] = 1 	imes 10$$^{-9}$$\ \mathrm{mol/L} at 25$$°C, what is its pH?

Accepted Answer

$$pH = 5$$

Question 12

A patient is given a medication that increases the $$[H^+] in $$their blood from $$1 	imes 10$$^{-7}$$\ \mathrm{mol/L} to$$ $$1 	imes 10$$^{-6}$$\ \mathrm{mol/L}. $$What happens to the blood pH?

Accepted Answer

It decreases by 1 unit.

Question 13

Which of the following best explains why phenolphthalein is colourless in acidic solutions but pink in basic solutions?

Accepted Answer

Phenolphthalein changes structure at higher pH, absorbing light differently.

Question 14

A solution has a pH of 2. What is its classification on the pH scale?

Accepted Answer

Acidic

Question 15

Which of the following is the correct relationship between pH and pOH at 25°C?

Accepted Answer

$$pH + pOH = 14$$

Question 16

A laboratory spill results in a solution with a pH of 12. Which of the following best describes the solution?

Accepted Answer

It is basic and has a low $$[H^+]$$ concentration.

Question 17

A student calculates the pH of a solution as 2.35 using a $$[H^+]$$ value with three significant digits. How many decimal places should the pH be reported to?

Accepted Answer

Three decimal places

Question 18

Which of the following best describes the colour change of litmus in a basic solution?

Accepted Answer

Red to blue

Question 19

A solution has a pH of 8.5. Which of the following is closest to its $$[H^+]$$ concentration?

Accepted Answer

$$[H^+] = 3.2 	imes 10$$^{-9}$$\ \mathrm{mol/L}$$

Question 20

Which of the following is a property of a weak acid?

Accepted Answer

It ionizes only partially in water.

Acids, Bases, and pH Calculations: Strong vs. Weak Acids

Study Guide - Practice Questions

Study Guide - Flashcards