AP Chemistry Unit 4 Review

Front

What is a precipitate?

Back

A precipitate is a solid that forms and settles out of a liquid mixture during a chemical reaction.

Front

What is the role of a conjugate acid-base pair in a chemical reaction?

Back

A conjugate acid-base pair consists of two species that transform into each other by the gain or loss of a proton (H+).

Front

What happens to the number of electrons in a substance that is reduced?

Back

The number of electrons in a substance that is reduced increases.

Front

What is an excess reagent in a chemical reaction?

Back

An excess reagent is the reactant that remains after the reaction has gone to completion.

Front

What is the solubility rule for precipitates?

Back

Most sulfates are soluble, but barium sulfate, lead sulfate, and calcium sulfate are exceptions that form precipitates.

Front

What is the difference between a strong acid and a weak acid?

Back

A strong acid completely dissociates in solution, while a weak acid only partially dissociates.

Front

What is the significance of the equilibrium constant (K) in a chemical reaction?

Back

The equilibrium constant (K) indicates the ratio of the concentrations of products to reactants at equilibrium.

Front

What is the difference between endothermic and exothermic reactions?

Back

Endothermic reactions absorb heat, while exothermic reactions release heat.

Front

What is the purpose of a titration in chemistry?

Back

A titration is used to determine the concentration of a solute in a solution by reacting it with a solution of known concentration.

Front

What is the pH scale?

Back

The pH scale measures the acidity or basicity of a solution, ranging from 0 (acidic) to 14 (basic), with 7 being neutral.