Exothermic and Endothermic Reaction-Lesson

​

Endothermic and Exothermic Reactions

Multiple Choice

First, let us review...

What are some signs that a chemical reaction has taken place?

• Change in shape

• Melting

• Bubbles of gas appear

• Dissolving

Multiple Choice

After you combine two substances together, a new substance forms. This would be an example of a ---

• physical change

• chemical change

​Endothermic Reaction

• ​Energy is absorbed into the reaction

• Endo- means to be absorbed or to enter

• Surroundings usually feel cool

Multiple Choice

In an endothermic reaction, energy is ---

• Absorbed

• Released

Multiple Choice

If a chemical reaction is endothermic, the temperature would ___ as it absorbs energy.

• Increase

• Decrease

• Stay the same

​Exothermic Reaction

• ​Energy is released into the reaction

• Exo- means to exit or to be released

• Surroundings usually feel hot

Multiple Choice

In an exothermic reaction, energy is ---

• Absorbed

• Released

Multiple Choice

If a chemical reaction is exothermic, the temperature would ___ as energy is released into the surroundings.

• Increase

• Decrease

• Stay the same

​Heat

• ​In exothermic reactions, heat moves out of the system.

• In endothermic reactions, heat moves into the system.

Multiple Choice

What instrument would you use to detect whether a reaction was endothermic or exothermic?

• Digital scale

• Thermometer

• Ruler

• Barometer

Multiple Choice

____ reactions usually feel cool.

• Endothermic

• Exothermic

Multiple Choice

Surrounding temperatures get warmer in ___ reactions.

• Endothermic

• Exothermic

Multiple Choice

The process of photosynthesis is an ____ reaction.

• Endothermic

• Exothermic

Multiple Choice

The initial temperature of a reaction measured to be 20^oC. The final temperature was 45^oC. The reaction was ---

• Endothermic

• Exothermic

Multiple Choice

A rocket launch is an example of an ___ reaction.

• Endothermic

• Exothermic

Multiple Choice

The initial temperature of a reaction measured to be 20^oC. The final temperature was 10^oC. The reaction was ---

• Endothermic

• Exothermic

Multiple Select

Which of the following are examples of endothermic reactions? Choose 2.

• Baking a cake

• Water evaporating

• Candles burning

• Water freezing

Multiple Select

Which of the following are examples of exothermic reactions? Choose 2.

• Baking a cake

• Water evaporating

• Candles burning

• Water freezing

Reaction Energy

Open Ended

What does "Activation" means?

Open Ended

In your own words. What is "activation energy"?

Lesson Objective

1. Compare and contrast endothermic and exothermic reactions.

2. Define activation energy.

Multiple Choice

If a chemical reaction is EXOTHERMIC, the energy stored in the reactants is....

• the same as the products

• greater than the products

• less than the products

Multiple Choice

In an endothermic reaction, heat is ...

• taken in or absorbed

• given out or released

Multiple Choice

How does a catalyst work in speeding up a reaction?

• By lowering the activation energy or reaction

• by making them more available

• by giving them more energy

Multiple Choice

Is this endothermic or exothermic?

• exothermic

• endothermic

Multiple Choice

Is this endothermic or exothermic?

• exothermic

• endothermic

Multiple Choice

Is this endothermic or exothermic?

• exothermic

• endothermic

Multiple Choice

In order to break bonds between atoms...

• energy is absorbed

• energy is released

• energy stays the same

• energy is cancelled

Multiple Choice

What happens to energy when bonds form between atoms?

• energy is absorbed

• energy is released

• energy is replaced

• energy is lost

Multiple Choice

In an exothermic reaction, more energy is released when the products form than is required to break the bonds.

• True

• False

Multiple Choice

When solid sodium bicarbonate was added to citric acid solution (Lab: Energy In, Energy out), the temperature decreased from 22°C to 10°C. Which description accurately models what happened?

• reactants + energy --> products

• reactants --> products + energy

• reactants + products = energy

• reactants --> energy

Multiple Choice

Did you know this is how a glow stick works? Pretty cool stuff! What is the best evidence that this is an exothermic reaction?

• light and small amounts of heat are given off

• color change

• popping noise as the glass inside it breaks

Multiple Choice

What type of reaction is modeled?

• endothermic

• exothermic

• this model is incorrect

Multiple Choice

What type of reaction is modeled?

• endothermic

• exothermic

• this model is incorrect

Multiple Choice

What happens to the energy from the sun in the leaf?

• The light energy is consumed by the leaf and can no longer be used.

• The light energy is used to break the bonds in the water and carbon dioxide molecules.

• The light energy is used to break the bonds in the sugar and oxygen molecules.

• The light is stored as small packets of energy in cells throughout the leaf.

Multiple Select

Which are true for exothermic reactions?

(select ALL that apply)

• energy is absorbed to break bonds

• energy is given off to form new bonds

• more energy is absorbed than given off

• more energy is given off than is absorbed

Multiple Select

Which are true for endothermic reactions?

(select ALL that apply)

• energy is absorbed to break bonds

• energy is given off to form new bonds

• more energy is absorbed than given off

• more energy is given off than is absorbed

Multiple Select

Where is energy absorbed in order to break bonds for this chemical reaction?

(select ALL that apply)

• A

• B

• C

• none of these

Multiple Select

Where is energy released when new bonds are formed in this chemical reaction?

(select ALL that apply)

• A

• B

• C

• none of these

Multiple Choice

Which is true for the citric acid solution?

• more energy is absorbed

• more energy is released

• energy is used up

• energy is created

Multiple Choice

Which is true for the sodium bicarbonate solution?

• more energy is absorbed

• more energy is released

• energy is used up

• energy is created

Multiple Choice

Chemical potential energy is the energy released when...

• atoms form bonds

• atoms break bonds

• atoms are converted to energy

• atoms are destroyed

Drag and Drop

In an endothermic reaction ​

Placeholder

is required to break the bonds of the reactants than is ​ ​

Placeholder

when products form.

Drag these tiles and drop them in the correct blank above

more energy

released

less energy

absorbed

Drag and Drop

In an exothermic reaction ​

Placeholder

is required to break the bonds of the reactants than is ​ ​

Placeholder

when products form.

Drag these tiles and drop them in the correct blank above

more energy

released

less energy

absorbed

Multiple Choice

A chemical reaction in which more energy is released when the products form than is required to break the bonds in the reactants.

• exothermic reaction

• endothermic reaction

• chemical reaction

• conservation of energy

Multiple Choice

A chemical reaction in which more energy is required to break the bonds of the reactants than is released when the products form.

• exothermic reaction

• endothermic reaction

• chemical reaction

• conservation of energy

Multiple Select

During a chemical reaction, energy is...

(select ALL that apply)

• created

• destroyed

• transferred

• conserved

Multiple Choice

During a chemical reaction, energy can get destroyed.

• True

• False

Multiple Choice

During a chemical reaction, energy can get created.

• True

• False

Multiple Choice

Energy is always conserved during a chemical reaction.

• True

• False