Diamond is an example of which type of crystalline solid?
Correct answer A. Covalent (network) crystal
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MDCAT ECAT Chemistry MCQs
Page 11 of MDCAT ECAT Chemistry multiple-choice questions with answers. Tap an option to check yourself.
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- Gases 40
- Liquids 40
- Solids 40
- Chemical Equilibrium 40
- Reaction Kinetics 40
- Thermochemistry and Energetics 40
- Electrochemistry 40
- Fundamental Concepts of Chemistry 40
- Atomic Structure 39
- Chemical Bonding 39
- Alcohols and Phenols 38
- Industrial Chemistry 37
- Aldehydes and Ketones 37
- Alkyl Halides 37
- s- and p-Block Elements 37
- Chemistry of Hydrocarbons 36
- Fundamental Principles of Organic Chemistry 36
- Carboxylic Acids 36
- Transition Elements 35
- Macromolecules 35
Why do metallic crystals conduct electricity in the solid state?
Correct answer A. They contain mobile valence electrons
Ice is a molecular crystal in which the molecules are held together mainly by ____
Correct answer C. hydrogen bonds
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Using lattice energy (KCl) = −718, ΔHsub(K) = +89, IE(K) = +419, ½BDE(Cl₂) = +122 and EA(Cl) = −349 kJ mol⁻¹, what is ΔHf of KCl?
Correct answer A. −437 kJ mol⁻¹
Which order of lattice energy (magnitude) is correct for the alkali metal fluorides?
Correct answer D. LiF > NaF > KF
How many atoms belong to one body-centred cubic (bcc) unit cell?
Correct answer A. 2
What is the coordination number of each atom in a cubic close-packed (face-centred cubic) metal crystal?
Correct answer C. 12
In the sodium chloride crystal, the six Cl⁻ ions surrounding each Na⁺ ion lie at the corners of a ____
Correct answer D. regular octahedron
Which crystal system has a = b ≠ c and α = β = γ = 90°?
Correct answer B. Tetragonal
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1.0 mol of PCl₅ is heated in a 1.0 dm³ vessel and is 20% dissociated at equilibrium (PCl₅ ⇌ PCl₃ + Cl₂). What is Kc?
Correct answer A. 0.05 mol dm⁻³
For N₂(g) + 3H₂(g) ⇌ 2NH₃(g), how is Kp related to Kc?
Correct answer C. Kp = Kc(RT)⁻²
For N₂(g) + 3H₂(g) ⇌ 2NH₃(g) at equilibrium, what happens when more H₂ is added at constant volume and temperature?
Correct answer C. The equilibrium shifts forward and more NH₃ forms
N₂O₄(g) (colourless) ⇌ 2NO₂(g) (brown) is endothermic in the forward direction. What is seen when the equilibrium mixture is heated?
Correct answer B. The brown colour deepens
How are the lobes of the dxy orbital oriented?
Correct answer D. Between the x and y axes
In which region of the electromagnetic spectrum do the lines of the Lyman series of hydrogen lie?
Correct answer B. Ultraviolet
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The Paschen series of hydrogen is produced when electrons fall to which energy level?
Correct answer C. n = 3
According to Hund’s rule, how are the three 2p electrons of a nitrogen atom arranged?
Correct answer C. One in each 2p orbital with parallel spins
Which configuration correctly represents a ground-state copper atom (Z = 29), an exception to the Aufbau order?
Correct answer C. [Ar] 3d¹⁰ 4s¹
What is the energy of the electron in the n = 3 orbit of a hydrogen atom (Eₙ = −13.6/n² eV)?
Correct answer D. −1.51 eV
How much energy is emitted when the electron of a hydrogen atom falls from n = 2 to n = 1 (Eₙ = −13.6/n² eV)?
Correct answer B. 10.2 eV