Acids and Bases Quiz

Ten Acids and Bases practice questions combine pH and neutralization calculations with concepts. Every answer is explained.

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For High school students and adults reviewing the topic.

About 14 minutes. 10 questions.

How does it work?

Choose one answer or enter a number in the stated unit, then check it.
Round only the final answer in a calculation.

What will you get?

Review a score and an explanation for every answer.

Question 1An ideal dilute solution has hydrogen-ion concentration 4.0 × 10⁻⁴ mol/L. Calculate pH as a number with no unit, rounded to two decimals.

Enter a number.

Answers within 0.005 of the expected value are accepted.

Question 2For an ideal dilute solution with pH 5.00, calculate hydrogen-ion concentration in mol/L. Round to six decimal places.

Enter a number in mol/L.

Answers within 0.0000005 mol/L of the expected value are accepted.

Question 3At 25 °C, a dilute aqueous solution has pOH 3.60. Use pH + pOH = 14.00 to find pH with no unit, rounded to two decimals.

Enter a number.

Answers within 0.005 of the expected value are accepted.

Question 4A sample contains 0.0075 mol of a strong monoprotic acid. A strong base supplies one OH⁻ per formula unit. Find the base needed for equivalence in mol, rounded to four decimals.

Enter a number in mol.

Answers within 0.00005 mol of the expected value are accepted.

Question 5In a proton-transfer reaction, one species accepts H⁺ from its partner. Which role does it play?

A spectator because proton transfer leaves reactions unchangedA base in that particular chemical reactionA proton donor in that same reactionAn oxidizing agent because a proton is an electron pair

Question 6Two acids have equal formal molarity but different fractions ionized in water. What distinguishes them?

Their temperatures because dissociation fraction is a thermometerTheir tendency to transfer protons to the solvent under those conditionsTheir concentrations despite the equal stated molarityTheir volumes because ionization measures container size

Question 7A weak acid and its conjugate base are present in substantial amounts. Why is a small acid addition less disruptive than in unbuffered water?

The weak acid turns added hydronium into dissolved oxygenThe solution prevents any added reagent from entering itThe base member consumes much of the added hydroniumThe pair forces the liquid to freeze before its pH changes

Question 8When mixed with ammonia, water supplies a proton to the ammonia molecule. Which feature permits this behavior?

Water’s oxygen nucleus releases a neutron during mixingAmmonia must first convert the water into a metalThe water molecule receives an additional proton in this stepWater’s molecular structure allows donation of H⁺ to a suitable partner

Question 9A concentrated aqueous sample is reported to have pH below zero. What should the interpretation recognize?

The scale has no fixed lower wall and activity mattersThe sample has no hydrogen ions because its pH is negativeThe instrument has measured mass instead of chemical activityThe result is impossible because pH counts negative molecules

Question 10A weak acid is titrated with a strong base to stoichiometric equivalence. Why does equivalence alone not establish a neutral final liquid?

The remaining conjugate ion reacts with the solventThe endpoint converts the remaining ions into inert atomsThe word equivalence requires equal solution volumesThe salt removes the need to consider aqueous equilibria

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