Calculating the necessary energy to recycle aluminum from aluminum oxide which was a question on the 2015 AP Chemistry exam. [6:16]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Biology 2e is designed to cover the scope and sequence requirements of a typical two-semester biology course for science majors. The text provides comprehensive coverage of foundational research and core biology concepts through an evolutionary lens. Biology includes rich features that engage students in scientific inquiry, highlight careers in the biological sciences, and offer everyday applications. The book also includes various types of practice and homework questions that help students understand—and apply—key concepts. The 2nd edition has been revised to incorporate clearer, more current, and more dynamic explanations, while maintaining the same organization as the first edition. Art and illustrations have been substantially improved, and the textbook features additional assessments and related resources.

By the end of this section, you will be able to do the following:

Define “energy”
Explain the difference between kinetic and potential energy
Discuss the concepts of free energy and activation energy
Describe endergonic and exergonic reactions

Paul Andersen describes the history of calorimetry and explains how it can be used to measure energy changes in a system. The specific heat of water is well established and so as a system releases or absorbs energy from a surrounding water bath it can be measured. [6:01]

Students act as engineers to learn about the strengths of various epoxy-amine mixtures and observe the unique characteristics of different mixtures of epoxies and hardeners. Student groups make and optimize thermosets by combining two chemicals in exacting ratios to fabricate the strongest and/or most flexible thermoset possible.

With an overview of topics related to chemical equilibrium, this site provides a foundation to a study of thermodynamics and energy. The site specifically addresses free energy and the Gibbs function.

Polymers are a vital part of our everyday lives and nearly all consumer products have a plastic component of some variation. Students explore the basic characteristics of polymers through the introduction of two polymer categories: thermoplastics and thermosets. During teacher demos, students observe the unique behaviors of thermoplastics. The fundamentals of thermoset polymers are discussed, preparing them to conduct the associated activity in which they create their own thermoset materials and mechanically test them. At the conclusion of this lesson-activity pair, students understand the basics of thermoplastics and thermosets, which may entice their interest in polymer engineering.

The students discover the basics of heat transfer in this activity by constructing a constant pressure calorimeter to determine the heat of solution of potassium chloride in water. They first predict the amount of heat consumed by the reaction using analytical techniques. Then they calculate the specific heat of water using tabulated data, and use this information to predict the temperature change. Next, the students will design and build a calorimeter and then determine its specific heat. After determining the predicted heat lost to the device, students will test the heat of solution. The heat given off by the reaction can be calculated from the change in temperature of the water using an equation of heat transfer. They will compare this with the value they predicted with their calculations, and then finish by discussing the error and its sources, and identifying how to improve their design to minimize these errors.

Students learn the fundamental concepts of heat transfer and heat of reaction. This includes concepts such as physical chemistry, an equation for heat transfer, and a basic understanding of energy and heat transfer.

Georgia State University Physics Department privides an incredibly thorough treatment of the laws of thermodynamics. Multiple pages; many informative graphics; opportunities to practice problems and receive immediate feedback.

Students explore material properties by applying some basic principles of heat transfer. They use calorimeters to determine the specific heat of three substances: aluminum, copper and another of their choice. Each substance is cooled in a freezer and then placed in the calorimeter. The temperature change of the water and the substance are used in heat transfer equations to determine the specific heat of each substance. The students compare their calculated values with tabulated data.

A video tutorial explaining the enthalpy of a reaction using an energy diagram. [2:42]

How does a hand warmer warm your hands? Find out with this demonstration of the exothermic reaction of water and sodium acetate in action. [2:24]

At this site, the student can find out thermophysical properties of different fluids and gases.