Unit 9 Review: Types of Reactions (Ellington)

Unit 9 Review: Chemical Reactions (Ellington)

Start at the beginning!

• Chemical reactions involve...

• reactants -> products

• building and/or breaking bonds to form new compounds

• plenty of observable indicators a reaction has happened.

Multiple Choice

Which are the reactants?

AB + C -> CB + A

• AB only

• C only

• CB + A

• AB + C

Open Ended

List at least 3 things a student would observe if a chemical reaction was happening. (HINT: Don't say bonds build or breaking, you can't directly observe that.)

Don't break the laws of physics!

• Matter can not be created or destroyed

• The mass of the reactants has to equal the mass of the products.

• If you do not have the same mass, human error and poorly used equipment are to blame.

Open Ended

A student measures the mass of a piece of magnesium to be 1.0g. The student burns the magnesium for a minute. The student measures the mass of all the powder products and remaining magnesium to be 0.8g. What is one reason the mass of the products could be less than the mass of the reactants?

Endo vs Exo

• Endothermic = System takes in heat to break bonds. Surroundings get colder.

• Exothermic = System gives off heat to build bonds. Surroundings get warmer.

Multiple Choice

When a chemical bond is built, a thermometer in the container with the reaction would...

• show an increasing temperature

• show an decreasing temperature

Multiple Choice

If a thermometer in a container with a reaction read a decreasing temperature, we can assume...

• The reaction is endothermic and breaking bonds

• The reaction is exothermic and building bonds

Speeding up Reactions

• Particles have to collide just right to react.

• More collisions = more reactions

• More high energy collisions = more reactions

Open Ended

We covered THREE ways to speed up a chemical reaction. Can you name at least two of them?

Last but not least: Types of reactions!

• Look at what is before and after the arrow!

• Find the pattern

• Don't forget about Combustion, students always forget that one exists.

Multiple Choice

Click the image.

• Decomposition

• Synthesis

• Single replacement

• Double replacement

• Combustion

Multiple Choice

Click the image.

• Decomposition

• Synthesis

• Single replacement

• Double replacement

• Combustion

Multiple Choice

Click the image.

• Decomposition

• Synthesis

• Single replacement

• Double replacement

• Combustion

Multiple Choice

Click the image.

• Decomposition

• Synthesis

• Single replacement

• Double replacement

• Combustion

Multiple Choice

Click the image.

• Decomposition

• Synthesis

• Single replacement

• Double replacement

• Combustion

Open Ended

What questions do you have? (I can see your name, but I will not say it out loud.)