MCQ Collection
MDCAT 2026 MCQs
Practice MDCAT 2026 questions with answers and explanations.
Choose an option to check your answer.
Correct Answer: B. A species that causes oxidation and is itself reduced
Explanation:
The oxidizing agent accepts electrons.
Its oxidation number decreases.
Choose an option to check your answer.
Correct Answer: C. A species that causes reduction and is itself oxidized
Explanation:
The reducing agent donates electrons.
Its oxidation number increases.
Choose an option to check your answer.
Correct Answer: D. An electrochemical cell producing electrical energy from a spontaneous reaction
Explanation:
A galvanic or voltaic cell converts chemical energy into electrical energy.
Electrons flow through an external circuit.
Choose an option to check your answer.
Correct Answer: D. 4
Explanation:
For the 1:1 equation, Kc=[B]/[A].
Kc=0.80/0.20=4.
Choose an option to check your answer.
Correct Answer: A. A substance changing color over a characteristic pH range
Explanation:
Acid-base indicators have differently colored protonated and deprotonated forms.
They help identify titration endpoints.
Choose an option to check your answer.
Correct Answer: A. 1
Explanation:
The equilibrium expression is Kc=[B]/[A]^2.
Kc=0.25/(0.50)^2=1.
Choose an option to check your answer.
Correct Answer: B. A quantitative method using a standard solution to determine unknown concentration
Explanation:
Titration uses a measured reaction stoichiometry.
The endpoint signals that the required amount of titrant has been added.
Choose an option to check your answer.
Correct Answer: B. Toward products
Explanation:
Because Q<K, more products must form.
The reaction proceeds forward until Q reaches K.
Choose an option to check your answer.
Correct Answer: C. Point where stoichiometrically equivalent acid and base amounts have reacted
Explanation:
The equivalence point is defined by reaction stoichiometry.
Its pH depends on acid and base strengths.
Choose an option to check your answer.
Correct Answer: C. A substance that increases H+ concentration in water
Explanation:
Arrhenius acids produce hydrogen ions in aqueous solution.
The model applies specifically to water.
Choose an option to check your answer.
Correct Answer: D. A substance that increases OH- concentration in water
Explanation:
Arrhenius bases increase hydroxide-ion concentration in water.
Many metal hydroxides fit this definition.
Choose an option to check your answer.
Correct Answer: A. A proton donor
Explanation:
Brønsted-Lowry acid-base reactions involve proton transfer.
The acid loses H+ to a base.
