Chemistry MDCAT MCQs

Organic, inorganic & physical chemistry MCQs

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Showing 305 MCQs in Chemistry
Chemistry
A. 0.5 mole
B. 1 mole
C. 2 moles
D. 1.5 moles
Answer: CaCO3 to CaO + CO2 is a 1:1 reaction, so 1 mole produces 1 mole of CO2.
Chemistry
A. Sugar solution
B. Sodium chloride solution
C. Distilled water
D. Ethanol
Answer: Sodium chloride solution conducts electricity because it dissociates into Na+ and Cl- ions.
Chemistry
A. NaCl
B. CCl4
C. KBr
D. MgO
Answer: CCl4 is formed by sharing electrons between carbon and chlorine atoms, making it covalent.
Chemistry
A. H2SO4
B. H2S
C. SO2
D. SCl2
Answer: Sulfuric acid (H2SO4) is an oxoacid because it contains oxygen, hydrogen, and sulfur.
Chemistry
A. 2, 8, 7
B. 2, 8, 8
C. 2, 8, 6
D. 2, 7, 8
Answer: Chlorine gains one electron to form Cl-, giving it 18 electrons arranged as 2, 8, 8 like argon.
Chemistry
A. 6, 8, 6
B. 6, 6, 8
C. 8, 6, 6
D. 6, 14, 6
Answer: Carbon-14 has 6 protons, 14 - 6 = 8 neutrons, and 6 electrons (neutral atom).
Chemistry
A. CH2=CH2 + H2 to CH3CH3
B. CH4 + Cl2 to CH3Cl + HCl
C. 2CH3CH2OH to CH3CH2OCH2CH3 + H2O
D. CH3COOH + NaOH to CH3COONa + H2O
Answer: In this reaction, hydrogen adds across the double bond of ethene to form ethane.
Chemistry
A. Methanoic acid
B. Ethanoic acid
C. Propanoic acid
D. Ethanal
Answer: CH3COOH has a two-carbon chain with a carboxyl group, giving it the IUPAC name ethanoic acid.
Chemistry
A. Acetic acid
B. Hydrochloric acid
C. Carbonic acid
D. Phosphoric acid
Answer: Hydrochloric acid (HCl) completely ionizes in water, making it a strong acid.
Chemistry
A. 2, 8, 2
B. 2, 8, 1
C. 2, 8, 7
D. 2, 7, 1
Answer: Sodium has 11 electrons arranged as 2, 8, 1 giving it one valence electron.
Chemistry
A. 11.2 L
B. 22.4 L
C. 44.8 L
D. 2.24 L
Answer: At standard temperature and pressure, 1 mole of an ideal gas occupies 22.4 L.
Chemistry
A. Melting
B. Sublimation
C. Condensation
D. Evaporation
Answer: Sublimation is the phase transition where a solid changes directly into gas without becoming liquid.
Chemistry
A. Sodium
B. Chlorine
C. Oxygen
D. Argon
Answer: Chlorine is a halogen and belongs to Group 17 of the periodic table.
Chemistry
A. Vanadium pentoxide
B. Iron
C. Platinum
D. Manganese dioxide
Answer: Iron is used as a catalyst in the Haber process for the synthesis of ammonia from N2 and H2.
Chemistry
A. Zero
B. 1 kJ/mol
C. -1 kJ/mol
D. Depends on the element
Answer: By convention, the standard enthalpy of formation of an element in its most stable form is zero.
Chemistry
A. Electron affinity
B. Ionization energy
C. Electronegativity
D. Lattice energy
Answer: Ionization energy is the minimum energy required to remove the most loosely bound electron from a gaseous atom.
Chemistry
A. Increases down the group
B. Decreases down the group
C. Remains constant
D. First increases then decreases
Answer: Atomic radius increases down a group because new electron shells are added at each period.
Chemistry
A. [Ar] 3d6
B. [Ar] 3d5
C. [Ar] 3d4
D. [Ar] 3d6 4s2
Answer: Fe has configuration [Ar] 3d6 4s2; losing 2 electrons from 4s gives [Ar] 3d6.
Chemistry
A. Increase in temperature
B. Decrease in temperature
C. Increase in pressure only
D. No change
Answer: Gas solubility in water increases as temperature decreases because kinetic energy of gas molecules reduces.
Chemistry
A. Na
B. KMnO4
C. Fe
D. Cu
Answer: KMnO4 contains Mn in +7 oxidation state and readily accepts electrons, making it a strong oxidizing agent.
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