OAT General Chemistry 4

Question 1

Which of the following salts will produce a basic solution when dissolved in water?

Accepted Answer

Na2CO3

Answer

Na2CO3 is the salt of a strong base (NaOH) and weak acid (H2CO3), so its solution is basic due to hydrolysis of CO3²⁻.

Question 2

What is the hybridization of the carbon atom in CO2?

Accepted Answer

sp

Answer

Carbon in CO2 forms two double bonds with no lone pairs, requiring sp hybridization with a linear geometry.

Question 3

The Ksp of AgCl is 1.8 × 10⁻¹⁰. What is the molar solubility of AgCl in pure water?

Accepted Answer

1.3 × 10⁻⁵ M

Answer

For AgCl → Ag⁺ + Cl⁻, Ksp = s² = 1.8×10⁻¹⁰, so s = √(1.8×10⁻¹⁰) ≈ 1.3×10⁻⁵ M.

Question 4

Which of the following colligative properties depends on the number of solute particles in solution?

Accepted Answer

Boiling point elevation

Answer

Boiling point elevation (ΔTb = Kb × m × i) is a colligative property that depends on solute particle concentration.

Question 5

Which of the following best describes a zero-order reaction?

Accepted Answer

Rate is independent of reactant concentration

Answer

In a zero-order reaction, the rate is constant and does not depend on the concentration of the reactant.

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