Exploring Exothermic and Endothermic Reactions

The video tutorial explains exothermic and endothermic reactions, focusing on how energy is stored in chemical bonds and represented in reaction profiles. It discusses the importance of activation energy and how it affects the initiation of reactions. Examples of exothermic reactions, such as combustion, and endothermic reactions, like the breakdown of calcium carbonate, are provided. The video also covers how to draw reaction profiles and indicates the energy changes during reactions.

What is the main difference between exothermic and endothermic reactions?

• Exothermic reactions absorb energy, while endothermic reactions release energy.

• Both exothermic and endothermic reactions release energy.

• Exothermic reactions release energy, while endothermic reactions absorb energy.

• Both exothermic and endothermic reactions absorb energy.

Tags

NGSS.HS-PS1-4

In a reaction profile, what does the y-axis represent?

• The progress of the reaction

• The temperature of the surroundings

• The speed of the reaction

• The total energy of the molecules

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NGSS.HS-PS1-4

Where are the reactants placed on a reaction profile?

• On the left

• At the bottom

• On the right

• At the top

What is the most common type of exothermic reaction?

• Combustion reactions

• Photosynthesis

• Oxidation reactions

• Neutralization reactions

Which of the following is an example of an exothermic reaction?

• Combustion of methane

• Breaking down calcium carbonate

• Melting ice

• Photosynthesis

Tags

NGSS.HS-PS1-4

What is required to break down calcium carbonate into calcium oxide and carbon dioxide?

• Heat

• Light

• Sound

• Electricity

Tags

NGSS.HS-PS1-4

In an endothermic reaction profile, where are the products placed relative to the reactants?

• Lower down

• At the same level

• Higher up

• To the left

Tags

NGSS.HS-PS1-4

What is activation energy?

• The total energy of the products

• The energy released during a reaction

• The minimum energy required for reactants to collide and react

• The energy absorbed during a reaction

How is activation energy represented on a reaction profile?

• As the energy level of the reactants

• As the energy level of the products

• As the highest point on the curve

• As the difference in energy between the reactants and the products

What happens to the activation energy if the curve on a reaction profile is drawn higher?

• The activation energy increases

• The activation energy decreases

• The activation energy becomes zero

• The activation energy remains the same