MCQ Collection
MDCAT Chemistry MCQs
Practice MDCAT Chemistry questions with answers and explanations.
Choose an option to check your answer.
Correct Answer: C. A process releasing heat to the surroundings
Explanation:
Exothermic processes have negative enthalpy change under the usual convention.
The surroundings gain heat.
Choose an option to check your answer.
Correct Answer: D. A process absorbing heat from the surroundings
Explanation:
Endothermic processes have positive enthalpy change.
The system gains heat.
Choose an option to check your answer.
Correct Answer: B. A solution containing more dissolved solute than equilibrium normally allows
Explanation:
Supersaturated solutions are metastable.
Crystallization can be triggered by a seed crystal or disturbance.
Choose an option to check your answer.
Correct Answer: C. Substances with similar polarity tend to dissolve one another
Explanation:
Polar solvents favor polar or ionic solutes.
Nonpolar solvents favor nonpolar solutes.
Choose an option to check your answer.
Correct Answer: D. A mixture with dispersed particles intermediate between solution and suspension size
Explanation:
Colloidal particles remain dispersed for long periods.
They can scatter light through the Tyndall effect.
Choose an option to check your answer.
Correct Answer: A. Scattering of light by colloidal particles
Explanation:
True solutions generally do not show visible light scattering.
Colloids make a light beam visible.
Choose an option to check your answer.
Correct Answer: B. 2.0 L
Explanation:
Use P1V1=P2V2.
V2=100×4.0/200 = 2.0 L.
Choose an option to check your answer.
Correct Answer: C. 3.0 L
Explanation:
Use V1/T1=V2/T2.
V2=2.0×450/300 = 3.0 L.
Choose an option to check your answer.
Correct Answer: D. 200 kPa
Explanation:
Use P1/T1=P2/T2.
P2=100×600/300 = 200 kPa.
Choose an option to check your answer.
Correct Answer: A. 0.987 mol
Explanation:
Use n=PV/RT.
N=100×24.6/(8.31×300)≈0.987 mol.
Choose an option to check your answer.
Correct Answer: B. 100 kPa
Explanation:
Dalton's law adds partial pressures.
20+35+45 = 100 kPa.
Choose an option to check your answer.
Correct Answer: C. 1.0 mol
Explanation:
Moles equal molarity times volume in liters.
0.50×2.0 = 1.0 mol.
