Question

Answer true or false to the following statements about energy diagrams and reactions. (a) A reaction coordinate diagram is used to visualize the change in the internal energy of chemical structures that occurs during chemical reactions. (b) Thermodynamics is the study of the energies of structures that are represented by wells on reaction coordinate diagrams. (c) Kinetics is the study of the rates of chemical reactions. (d) One part of a reaction mechanism would be the understanding of which bonds break and form during a reaction. (e) Thermal reactions occur via collisions between molecules, and the more energy in those collisions, the greater the rate of the reactions. (f) The enthalpy of a reaction is the sole determinant of whether it will occur. (g) An exergonic reaction will always occur during the life span of the standard human being.

Short answer

a) A reaction coordinate diagram is a graphical representation that helps visualize the change in the internal energy of chemical systems during chemical reactions. b) Thermodynamics is the study of the energies of structures, which includes the understanding of energy wells in a reaction coordinate diagram. c) The enthalpy of a reaction is the sole determinant of whether it will occur. d) Exergonic reactions release energy but do not necessarily occur during the life span of a human being due to other factors such as reaction rate or kinetic factors. Answer: c) The enthalpy of a reaction is the sole determinant of whether it will occur.

Step-by-step solution

(a) Reaction coordinate diagram

True. A reaction coordinate diagram is indeed a graphical representation that helps visualize the change in the internal energy of chemical structures during chemical reactions.

(b) Thermodynamics

True. Thermodynamics is the study of the energies of structures, which includes the understanding of energy wells in a reaction coordinate diagram.

(c) Kinetics

True. Kinetics focuses on the study of the rates of chemical reactions and how different factors affect these rates.

(d) Reaction mechanisms

True. One part of a reaction mechanism is the understanding of which bonds break and form during a reaction, which helps to explain the observed reaction rates.

(e) Thermal reactions

True. Thermal reactions occur via collisions between molecules, and an increase in their energy results in a greater rate of those reactions.

(f) Enthalpy

False. The enthalpy of a reaction is not the sole determinant of whether it will occur. Other factors such as entropy and temperature also contribute to the overall reaction's feasibility.

(g) Exergonic reactions

False. While exergonic reactions release energy, it does not guarantee that these reactions will occur during the life span of a human being. The reaction rate may still be too slow, or there may be other kinetic factors (activation energy, reactant concentration, etc.) that prevent the reaction from occurring.