Skip to main content
Ch.15 - Chemical Kinetics
Chapter 15, Problem 59

The diagram shows the energy of a reaction as the reaction progresses. Label each blank box in the diagram.
a. reactants b. products c. activation energy (Ea) d. enthalpy of reaction (ΔHrxn)

Verified step by step guidance
1
Identify the starting point of the reaction on the energy diagram, which represents the energy level of the reactants. Label this point as 'reactants'.
Locate the ending point of the reaction on the energy diagram, which represents the energy level of the products. Label this point as 'products'.
Find the peak of the energy curve, which represents the highest energy point during the reaction. The difference in energy between this peak and the reactants is the activation energy (E_a). Label this difference as 'activation energy (E_a)'.
Determine the difference in energy between the reactants and the products. This difference is the enthalpy of reaction (ΔH_rxn). Label this difference as 'enthalpy of reaction (ΔH_rxn)'.
Ensure that each label corresponds to the correct part of the energy diagram, reflecting the energy changes throughout the reaction process.

Verified Solution

Video duration:
1m
This video solution was recommended by our tutors as helpful for the problem above.
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Reactants and Products

In a chemical reaction, reactants are the starting substances that undergo a transformation, while products are the substances formed as a result of the reaction. Understanding the difference between these two is crucial for analyzing reaction diagrams, as they represent the initial and final states of the reaction.
Recommended video:
Guided course
00:53
Production of Hydrogen Example

Activation Energy (Eₐ)

Activation energy is the minimum energy required for a chemical reaction to occur. It represents the energy barrier that must be overcome for reactants to be converted into products. This concept is essential for understanding the energy profile of a reaction, as it indicates how much energy is needed to initiate the process.
Recommended video:
Guided course
02:02
Activity Series Chart

Enthalpy of Reaction (ΔH₍rxn₎)

The enthalpy of reaction, denoted as ΔH₍rxn₎, is the change in heat content during a chemical reaction at constant pressure. It indicates whether a reaction is exothermic (releases heat) or endothermic (absorbs heat). This concept is vital for interpreting the energy changes depicted in reaction diagrams, as it helps to determine the overall energy shift from reactants to products.
Recommended video:
Guided course
02:34
Enthalpy of Formation