2 mol of solute is dissolved to make 2 L of solution. Enter molarity.
Correct Answer: 1
Explanation:
M=n/V=2/2=1.000 mol/L.
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A substance has molar mass 28 g/mol. Enter the mass of 1 mol in grams.
Correct Answer: 28
Explanation:
Use mass = amount × molar mass. Therefore mass = 1 × 28 = 28 g.
Practice context 4: Which statement correctly identifies the limiting reagent?
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Correct Answer: D. The limiting reagent is consumed first and determines the maximum product amount
Explanation:
The limiting reagent runs out first under the balanced stoichiometric ratio and caps theoretical yield.
Organic formula item 4: Which formula contains C=1 and H=4 as stated?
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Correct Answer: C. C1H4
Explanation:
The requested molecular formula contains exactly 1 carbon and 4 hydrogen atoms.
Practice context 4: How does a catalyst affect a reversible reaction?
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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.
Practice context 4: Which redox statement is correct?
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Correct Answer: A. 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.
Practice context 4: Which statement best describes a covalent bond?
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Correct Answer: A. A covalent bond forms through sharing electron density between atoms
Explanation:
Covalent bonding arises from shared electron density, commonly between nonmetal atoms.
Practice context 4: Which periodic-trend statement is most accurate?
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Correct Answer: C. 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.
Practice context 4: Which statement is consistent with Le Châtelier’s principle?
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Correct Answer: A. 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.
Acid calculation item 4: A strong monoprotic acid has [H⁺]=1e-05 mol/L. Enter the pH.
Correct Answer: 5
Explanation:
pH=−log₁₀[H⁺]=−log₁₀(1e-05)=5.0.
1 mol of solute is dissolved to make 6 L of solution. Enter molarity.
Correct Answer: 0.167
Explanation:
M=n/V=1/6=0.167 mol/L.
A substance has molar mass 26 g/mol. Enter the mass of 5 mol in grams.
Correct Answer: 130
Explanation:
Use mass = amount × molar mass. Therefore mass = 5 × 26 = 130 g.