Journal Entry:

Hydrogen is considered the clean fuel of the future for automobiles. The simple chemistry behind the technology to produce water and 286 kJ of heat (per mole of hydrogen used).

1. Write the chemical equation for this reaction. Balance it.

2. What is the net energy input or output of the reaction as written?

3. What kind of energy exchange would you expect if you completed the reverse reaction and formed hydrogen and oxygen from water? Explain your thinking.

Learning Intentions

• We will learn how to use energy diagrams to compare forward and reverse reactions.
• We will learn how to explain changes in kinetic and potential energy in chemical reactions.

Closing Task:

You can draw a energy diagram for both endothermic and exothermic reactions and label all parts.

Content Standards being covered in this unit:

Students can develop a model to illustrate that the release or absorption of energy from a chemical reaction system depends upon the changes in total bond energy.(HS-PS1-4 and CCC Energy and Matter) .