7.4.3-Energy Changes & Chemical 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

Multiple Choice

____ reactions usually feel cold.

• endothermic

• exothermic

Multiple Choice

During an exothermic reaction, heat is _________ and chemical bonds __________.

• released, formed

• absorbed, broken

• released, broken

• absorbed, formed

Multiple Choice

During an endothermic reaction, heat is ________ and chemical bonds _______.

• released, formed

• absorbed, broken

• released, broken

• absorbed, formed

Multiple Choice

_____ reactions usually feel hot!

• endothermic

• exothermic

Multiple Choice

In an endothermic reaction, energy is _________.

• absorbed

• released

​JUST READ THIS:

Since energy always moves from hot to cold...

Multiple Choice

How does heat from thermal energy move?

• move from hot to cold
• moves from cold to hot  
• moves up and never down
• moves from side to side

Multiple Choice

When particles are heated they begin to ____.

• move faster

• mover slower

• move up

• jump out of the pot

Multiple Choice

When do particles move faster?

• In hot water

• In cold water

Multiple Choice

In heat transfer, heat always flows from the _______________ substance to the _______________ substance.

• Hotter to colder

• Colder to hotter

• Hotter to hotter

• Colder to colder

Multiple Choice

Molecules in cold things move more _________
than in hot things.

• quickly
• slowly
• happily
• merrily

Reaction Rate

• the SPEED at which reactants are converted into products in a reaction

Multiple Choice

In order to determine the rate of a reaction would you measure the reactions

• temperature

• mass of the product over time

Rates of Reaction

• concentration

• pressure

• surface area

• temperature

Open Ended

What makes carbon monoxide known as toxic and poisonous gas?

Multiple Choice

Catalyst is the opposite of an inhibitor... a catalyst will

• speed up a reaction

• slow down a reaction

Poll

How do you feel about endothermic and exothermic reaction and the rates of reactions?

• 5

• 4

• 3

• 2

• 1