Check for Understanding #2
October 23/26
1. Identify: the parts of this chemical reaction: A + B  AB
A and B in this reaction are known as reactants, and AB is the product.
2. Diagram: the energy changes that can take place in a chemical
reaction.
Exothermic: energy from the reactant is higher than that of the product.
Endothermic: energy is absorbed, so more energy is found in the
product than the reactants.
3. Explain: why the number of atoms of reactants must equal the number
of atoms of products formed.
There must be an equal amount of energy on both sides of the equation.
No energy is gained or lost.
4. Describe: the importance of enzymes to living organisms.
Enzymes speed up the chemical reactions in the bodies of living
organisms so they can survive.
5. For the following chemical reaction, label the reactants and products,
and then balance the chemical equation. _H2O2__H20 + 02
reactants: H2O+O2, product: H2O2;
2H2O22H2O+O2
6. Draw a diagram of a roller coaster and write a paragraph relating the
ride to activation energy and a chemical reaction.
When a roller coaster begins up a hill, it gains potential energy.
Once it starts down a hill, that energy is released as kinetic energy. The
activation energy is needed just to get the roller coaster up the hill. Then
energy continues to transfer from potential and kinetic and vice-versa.