Chemical Reactions and Energy Changes

The video tutorial covers chemical change graphs, focusing on endothermic and exothermic reactions. It explains photosynthesis as an endothermic process and cellular respiration as exothermic. The tutorial details how to graph these reactions, calculate energy changes, and the role of activation energy. It also discusses how catalysts lower activation energy, facilitating reactions.

What is the main focus of chemical change graphs?

• Physical changes in matter

• Chemical reactions and energy changes

• The structure of atoms

• The periodic table

Which process in plants is an example of an endothermic reaction?

• Fermentation

• Photosynthesis

• Cellular respiration

• Combustion

What type of reaction is cellular respiration?

• Neutral

• Endothermic

• Exothermic

• Reversible

In an endothermic reaction graph, what does a positive slope indicate?

• Energy is being released

• Energy is constant

• Energy is being absorbed

• No energy change

What is activation energy?

• The energy at the end of a reaction

• The energy released during a reaction

• The energy required to start a reaction

• The energy that remains constant

How does the law of conservation of energy apply to exothermic reactions?

• Energy is not involved

• Energy is transferred equally

• Energy is destroyed

• Energy is created

In an exothermic reaction graph, what does a negative slope indicate?

• Energy is being absorbed

• Energy is being released

• No energy change

• Energy is constant

What role does a catalyst play in a chemical reaction?

• Lowers the activation energy

• Increases the activation energy

• Increases the final energy

• Stops the reaction

Does a catalyst make a reaction occur that otherwise wouldn't?

• Yes, it changes the reaction path

• Yes, it creates new reactions

• No, it stops reactions

• No, it only speeds up existing reactions

In the example problem, what is the total energy change if the initial energy is 100 joules and the final energy is 350 joules?

• 300 joules

• 250 joules

• 150 joules

• 350 joules