Semester 2 Chemistry Multiple Choice

What operation generally makes a solid solute dissolve faster in a liquid solvent?

Crushing the solute to a powder.

What happens when a small crystal of solute is added to an unsaturated solution?

The crystal will dissolve.

What volume of a 1.0 molar sulfuric acid is needed to prepare 2.0 liters of a 0.25 molar solution?

500 milliliters.

Which of the following is not an example of a colligative property?

Color change.

Which compound produces the greatest freezing point depression?

CaCl2.

What is the molality of a solution containing 1 mol of solute in 2 kg of solvent?

1.0 m.

What type of solution contains more solute than it can theoretically hold at a given temperature?

Supersaturated.

What does 'like dissolves like' mean?

Polar solutes dissolve in polar solvents.

Which factor does not affect the solubility of a gas in a liquid?

Volume of solute.

What change will increase the rate of a chemical reaction?

Increasing concentration.

What is activation energy?

The energy needed to start a reaction.

What does a catalyst do in a chemical reaction?

Speeds up the reaction without being consumed.

How does the rate of a chemical reaction change with temperature?

Decreases as the concentration of the reactants decreases.

What will not affect the equilibrium position of a reversible reaction?

A catalyst is added.

What happens when a catalyst is used in a reaction?

The energy of activation for the reaction decreases.

Which system has the greatest entropy?

10 mL of water vapor at 101 °C.

Which chemical/physical change shows decreasing entropy?

None of these.

Which combination makes the most efficient buffer?

NaCN and HCN.

What is the pH of a 0.010 M HNO3 solution?

Approximately 2.

Identify the Brønsted-Lowry base and conjugate base in the reaction CN⁻ + H2O ⇌ HCN + OH⁻.

H2O and OH⁻.

Which produces a solution with pH ≈ 7?

KCl.

Which forms a weak acid solution?

CH3COOH.

What is a Lewis base?

Donates a pair of electrons.

What color does a solution with [H⁺] = 6.0 × 10⁻⁴ M turn with phenolphthalein?

Colorless.

How is benzoic acid classified based on its Ka value?

Relatively weak H⁺ donor.

What is the conjugate base of chlorous acid (HClO₂)?

ClO₂⁻.

What happens in a reaction with strong acid added to HCN/CN⁻ buffer?

CN⁻ + H⁺ → HCN.

Where does oxidation occur in a voltaic cell?

At the anode.

Who is the reducing agent in the reaction 2Na + 2H2O → 2NaOH + H2?

Na.

In the potassium and chlorine reaction (2K + Cl2 → 2KCl), what happens to K?

K is oxidized to K⁺.

What is electrolysis?

Electrical energy causes a chemical change.

In which compound is sulfur NOT +6?

S2O3²⁻.

Which is NOT a reduction?

Losing electrons.

How can you distinguish the electrolysis of water?

All of the above.

What is the anode when plating silver onto a teaspoon?

Silver rod.

In the reaction H⁺ + HSO3⁻ → H2O + SO2, what is reduced?

Not a redox reaction.