AP CHEM Unit 6 In Class Review

Front

What is an activated complex in a chemical reaction?

Back

An activated complex, or transition state, is a temporary, unstable arrangement of atoms that occurs during the transformation of reactants into products. It represents the highest energy state along the reaction pathway.

Front

What is the rate of a reaction?

Back

The rate of a reaction is the change in concentration of a reactant or product per unit time. It can be expressed in terms of molarity per second (mol/L·s).

Front

Define activation energy.

Back

Activation energy is the minimum energy required for a chemical reaction to occur. It is the energy barrier that must be overcome for reactants to be converted into products.

Front

What is the difference between an exothermic and an endothermic reaction?

Back

An exothermic reaction releases energy (usually in the form of heat) to the surroundings, while an endothermic reaction absorbs energy from the surroundings.

Front

How does a catalyst affect a chemical reaction?

Back

A catalyst increases the rate of a chemical reaction by lowering the activation energy, allowing the reaction to proceed more quickly without being consumed in the process.

Front

What is a rate law in chemistry?

Back

A rate law is an equation that relates the rate of a reaction to the concentration of reactants. It is typically expressed in the form: rate = k[A]^m[B]^n, where k is the rate constant, and m and n are the orders of the reaction with respect to reactants A and B.

Front

What does the slope of a concentration vs. time graph represent?

Back

The slope of a concentration vs. time graph represents the rate of the reaction. A negative slope indicates a decrease in concentration of reactants over time.

Front

What is the significance of the units of the rate constant (k)?

Back

The units of the rate constant (k) depend on the overall order of the reaction. For a first-order reaction, the units are s^-1; for a second-order reaction, the units are L·mol^-1·s^-1.

Front

What is the purpose of a reaction pathway diagram?

Back

A reaction pathway diagram visually represents the energy changes during a chemical reaction, showing the energy of reactants, products, and the activated complex, as well as the activation energy.

Front

What is the relationship between temperature and reaction rate?

Back

Generally, an increase in temperature increases the reaction rate because it provides more energy to the reactants, leading to a higher frequency of effective collisions.