AP Chem Midterm Review Questions

Front

What is Le Chatelier's Principle?

Back

Le Chatelier's Principle states that if a system at equilibrium is subjected to a change in concentration, temperature, or pressure, the system will adjust to counteract that change and restore a new equilibrium.

Front

Define equilibrium constant (K).

Back

The equilibrium constant (K) is a numerical value that expresses the ratio of the concentrations of products to reactants at equilibrium for a reversible reaction at a given temperature.

Front

What does a large K value indicate about a reaction?

Back

A large K value (K > 1) indicates that at equilibrium, the concentration of products is much greater than that of reactants, favoring the formation of products.

Front

What does a small K value indicate about a reaction?

Back

A small K value (K < 1) indicates that at equilibrium, the concentration of reactants is greater than that of products, favoring the formation of reactants.

Front

What is the relationship between ΔG° and K?

Back

The relationship is given by the equation ΔG° = -RT ln(K). A negative ΔG° corresponds to K > 1, indicating a spontaneous reaction.

Front

What is the significance of bond energy in chemical reactions?

Back

Bond energy is the amount of energy required to break a bond between two atoms. It is significant because it helps determine the overall energy change during a chemical reaction.

Front

What is the formula for calculating the energy change (ΔH) in a reaction?

Back

ΔH = Σ (bond energies of reactants) - Σ (bond energies of products). This formula helps to calculate the enthalpy change of a reaction.

Front

What is oxidation in terms of electron transfer?

Back

Oxidation is the process in which an atom, ion, or molecule loses electrons, resulting in an increase in oxidation state.

Front

What is reduction in terms of electron transfer?

Back

Reduction is the process in which an atom, ion, or molecule gains electrons, resulting in a decrease in oxidation state.

Front

What is the standard cell potential (E°cell)?

Back

The standard cell potential (E°cell) is the measure of the voltage produced by an electrochemical cell under standard conditions (1M concentration, 1 atm pressure, and 25°C).