Question 1

Which of the following statements best describes an exothermic reaction?

Accepted Answer

The reaction gives off heat to the surroundings, and $$\Delta H is $$negative.

Question 2

Which equation correctly represents the relationship between free energy, enthalpy, entropy, and temperature?

Accepted Answer

$$\Delta G = \Delta H - T\Delta S$$

Question 3

A reaction has $$\Delta G \u003c 0. $$Which of the following is true?

Accepted Answer

The reaction is spontaneous and does not require energy input.

Question 4

Which of the following factors will NOT increase the rate of a chemical reaction?

Accepted Answer

Decreasing the concentration of reactants

Question 5

Which of the following best describes the role of enzymes in biological systems?

Accepted Answer

Enzymes lower the activation energy and increase the reaction rate.

Question 6

Which of the following is a decomposition reaction?

Accepted Answer

$$2KClO_3 \rightarrow 2KCl + 3O_2$$

Question 7

Which of the following statements about reversible reactions is correct?

Accepted Answer

At equilibrium, the rates of the forward and reverse reactions are equal.

Question 8

Combustion of a hydrocarbon always produces which of the following products?

Accepted Answer

Carbon dioxide and water

Question 9

Which of the following is true about oxidation and reduction in inorganic reactions?

Accepted Answer

Oxidation is the loss of electrons, and reduction is the gain of electrons.

Question 10

Which of the following is an example of an organic oxidation reaction?

Accepted Answer

Conversion of an alcohol to an aldehyde

Question 11

Which of the following best describes a condensation reaction?

Accepted Answer

A reaction in which two molecules join together and water is produced.

Question 12

Which of the following statements about hydrolyzable lipids is correct?

Accepted Answer

They contain ester functional groups that can react with water to form carboxylic acids and alcohols.

Question 13

During the hydrogenation of an alkene, what is the result?

Accepted Answer

A double bond is converted to a single bond by the addition of two hydrogen atoms.

Question 14

According to Markovnikov’s rule, during the hydration of an asymmetric alkene, the hydrogen atom will add to:

Accepted Answer

The carbon with more hydrogen atoms attached

Question 15

Which of the following best describes the function of ATP in living systems?

Accepted Answer

ATP is the main molecule that transfers energy for cellular work.

Question 16

Which of the following is true about catalysts?

Accepted Answer

Catalysts lower the activation energy and can be used repeatedly.

Question 17

Which of the following is a correct statement about entropy ($$\Delta S$$)?

Accepted Answer

A positive $$\Delta S$$ means the system becomes more random.

Question 18

Which of the following is an example of a hydrolysis reaction in biological systems?

Accepted Answer

Breakdown of ATP to ADP and phosphate

Question 19

Which of the following best describes an exchange (displacement) reaction?

Accepted Answer

A reaction that involves both synthesis and decomposition steps.

Question 20

Which of the following is true about the combustion of fats compared to carbohydrates?

Accepted Answer

Fats produce more energy per gram than carbohydrates.

Chapter 5: Chemical Reactions – Thermodynamics, Kinetics, and Organic Mechanisms

Study Guide - Practice Questions