Its a little early for snow!

Ok so we can’t make real snow.

But let’s find out if we can make some chemical snow!

Lets get ready for lab.

• Gather your safety equipment.• You will need to wear your goggles

for this experiment.• Also we don’t want to smell or even waft

the liquids we are using today in class.

Signs of Chemical Change

• There are a number of observations that indicate a chemical reaction has occurred.

• Today you will observe some signs of chemical change in a lab.

Formation of Precipitate

One is the formation of a precipitate. A precipitate is a solid formed in a chemical reaction that is different from either of the reactants.

Liquid + Liquid New Solid formed

First set up your journal:Title: Precipitate Lab

Guiding Question: How do I know a chemical change happened?

Chart:

I notice…. I wonder….

Step 1

• Look at the clear liquid in the plastic cup (Epsom Salt, MgSO4 dissolved in Water, H2O).

• Write down some of the characteristics of the liquid in I notice column.

• Draw a picture of what everything looks like Before we test. Label your picture “Before”

Step 2

• Examine the yellow liquid(Ammonia NH3 ), remember you don’t want to smell this stuff. Trust me it smells bad! Also remember not to drink anything from the lab.

• Write down some of the characteristics of the liquid in I notice column.

• In your journal write what you Notice and what you Wonder. Look closely.

• Illustrate what you see After mixing. Label your picture “After”

Step 3

• Add 10 drops of the yellow (Ammonia NH3 ) liquid to the salt water in the cup.

• In your journal write what you Notice and what you Wonder. Look closely.

• Illustrate what you see After mixing. Label your picture “After”

• Check the mixture after 5 minutes, has it changed more?

Clean Up Time!

• All of these materials can be rinsed down the sink, we just want to be sure that we run water down the sink as well.

Ok so now it is clean up time!

All of these materials can be rinsed down the sink, we just want to be

sure that we run water down the sink as well.