MCQ Collection
China MCQs
Practice China questions with answers and explanations.
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Correct Answer: D. Increasing pressure shifts a gaseous equilibrium toward the side with fewer gas moles
Explanation:
A pressure increase favours the side occupying less gaseous volume; a catalyst changes rate, not equilibrium position.
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Correct Answer: A. Across a period, effective nuclear charge generally increases and atomic radius tends to decrease
Explanation:
Across a period, increasing nuclear charge with similar shielding pulls valence electrons closer.
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Correct Answer: B. A covalent bond forms through sharing electron density between atoms
Explanation:
Covalent bonding arises from shared electron density, commonly between nonmetal atoms.
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Correct Answer: C. Oxidation is an increase in oxidation number and reduction is a decrease
Explanation:
Oxidation corresponds to electron loss/increased oxidation number; reduction is the opposite.
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Correct Answer: B. A catalyst lowers activation energy for both forward and reverse reactions
Explanation:
It provides a lower-energy pathway in both directions, speeding equilibrium without changing K.
Correct Answer: 40
Explanation:
Use mass = amount × molar mass. Therefore mass = 2 × 20 = 40 g.
Correct Answer: 0.667
Explanation:
M=n/V=2/3=0.667 mol/L.
Correct Answer: 2
Explanation:
pH=−log₁₀[H⁺]=−log₁₀(1e-02)=2.0.
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Correct Answer: B. Meiosis reduces chromosome number and creates variation through independent assortment and recombination
Explanation:
Meiosis forms haploid cells and generates variation through chromosome segregation and recombination.
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Correct Answer: D. Each new DNA molecule contains one parental strand and one newly synthesised strand
Explanation:
DNA replication is semiconservative and uses complementary base pairing.
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Correct Answer: B. Enzymes lower activation energy without being consumed by the reaction
Explanation:
Enzymes catalyse reactions by lowering activation energy; conditions influence their structure and rate.
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Correct Answer: B. Light reactions generate ATP and reducing power used in carbon fixation
Explanation:
Light reactions provide ATP and NADPH, while the Calvin cycle fixes carbon into organic molecules.
