Curated OER
Catalytic Converter
Two animated slides explain the decomposition reactions that occurs within a catalytic converter. An enthalpy diagram is displayed. Hess's Law is demonstrated. Finally, the analogy of football is used to explain Hess's Law. This clever...
Pingry School
Heat of Reaction and Hess's Law
Melting and burning might seem like opposites, but both exist as common examples of exothermic reactions. Scholars work with three different exothermic chemical reactions to determine the enthalpy changes. They measure and mix chemicals,...
Net Texts
Hess's Law Worksheet
Challenge young scholars' understanding of thermochemistry with this skills-practice learning exercise on Hess's Law. Given a series of five multi-step chemical reactions, students must determine the overall change in entropy for each.
Curated OER
Heat of Formation using Hess's Law Lab
In this heat of formation learning exercise, students determine the heat of formation for magnesium by combining 3 given reactions and using Hess's Law. Students then complete a data calculations chart for each reaction.
Curated OER
Heat of Reaction
In this reactions worksheet, students define enthalpy, heat of formation, and Hess's Law. Students determine how many kilojoules are released during specific reactions. This worksheet has 6 short answer questions and 11 problems to solve.
Curated OER
Challenging Thermodynamics Problems
In this thermodynamics activity, students apply Hess's Law and review internal energy theory and heat capacity theory. Students use Boltzmann formula to calculate entropy and calculate the change in free energy. This activity has 12...
Curated OER
The Enthalpy of Chemical Change
In this chemical change worksheet, learners review enthalpy and use Hess's law to calculate enthalpy and the heat of reaction for given reactions. This worksheet has 3 problems to solve.
California State University
California State University: Hess' Law
Interactive site that generates random Hess's Law problems for you to solve. Allows you immediate feedback on your ability to use Hess's Law.
Dartmouth College
Dartmouth College: Chem Lab: Calorimetry 1 Enthalpy of Formation of Mg O
In this lab experiment students are asked to determine the standard molar enthalpy of formation of magnesium oxide, MgO. Students are asked to use Hess's Law and the enthalpy changes of several other solution reactions during this...
CK-12 Foundation
Ck 12: Hess's Law and Standard Enthalpy of Formation
[Free Registration/Login may be required to access all resource tools.] Students will use Hess's law of heat summation to add chemical reactions together to produce a desired final equation, and then calculate the enthalpy change for...
Chemistry Collective
Chem Collective: Heats of Reaction: Hess's Law
This activity provides a demonstration of Hess's Law using three reactions: the solubility NaOH in water, the solubility NaOH in HCl, and the reaction of a solution of HCl and a solution of NaOH.
Texas Instruments
Texas Instruments: Hess's Law Lesson
Students can use TI InterActive! to explore Hess's Law and the conservation of energy during reactions.
Simon Fraser University
Chem1 Virtual Textbook: Hess' Law and Thermochemical Calculations
With an overview of topics related to chemical energetics, this site provides a foundation to a study of thermodynamics and its relation Hess's law and enthalpies of combustion.
Michael Blaber, PhD
Florida State University: Thermochemistry: Hess's Law
This article from the Florida State University provides an excellent explanation of WHY Hess's Law works and examples of how to use the law. Common mistakes are identified and explained.
Dartmouth College
Dartmouth College: Chem Lab: Welcome to General Chemistry Laboratory!
Geared towards helping Dartmouth College students starting General Chemistry Laboratory, this site offers resources important for anyone in the lab. Learn why you should keep a lab notebook and how to keep yourself and others safe. This...
Other
Austin Community College: Handout on Enthalpy
A step-by-step example of how to complete Hess's Law problems. This example includes all the manipulations that may be required for Hess's Law.
Other
Dr. Rod Beavon: The Solubility of Ionic Compounds
A detailed discussion of solubility as a function of Enthalpy and Entropy. Goes way beyond the standard solubility discussion.
State University of New York
State University of New York: Hess's Law
Because reactions can be considered "additive," a series of reactions can be written like simultaneous mathematical equations and a net reaction determined by addition. To use this simulation, select individual reactions from the three...
Physics4kids
Physics4 kids.com: Thermodynamics & Heat: Enthalpy
Concise information about enthalpy, the measure of the total energy of a thermodynamic system.
Crescent Public Schools
The Internet Science Room: Enthalpy and Heat
Students learn about thermodynamics and enthalpy through practice problems and examples in this chemistry lesson.
Other
University of Texas at Dallas: Attractions in Compounds
Explanation of attractive forces and energy changes involved in bonding.
Upper Canada District School Board
Tom Stretton's Advanced Placement Chemistry: Thermochemistry
This chemistry e-textbook provides students with AP-level reading and practice material on thermochemistry.