Chemistry: The Stories

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BASICS

We have learned:

• Counting atoms
• Balancing equations
• Elements

We will learn:

• What is a precipitate?
• What is a catalyst?
• Classifying chemical reactions

WHAT IS A PRECIPITATE?

A precipitate is basically an undissolved solid in the chemical equation. The precipitate will always be on the product side of the equation because the reactants have all been transformed. There are none that are left to be a precipitate. So the precipitate is ALWAYS on the product side of the equation. Let’s look at some examples.

WHAT IS A CATALYST?

The catalyst helps the reaction go forward. It is not actually part of the reaction, it just helps it along. Actually, the catalyst is there to affect the rate of the reactions. It doesn’t always go forward, sometimes it make the reaction go slower.

Sometimes, the catalyst helps the reaction by making it go a lot faster. Sometimes, though, the reaction is slowed down by the catalyst.

CLASSIFYING CHEMICAL REACTIONS

There are different types of chemical reactions. Not just one, there are multiple. Let’s discover more.

1. The Synthesis reaction

The synthesis reaction is when 2 become 1

Example: C + O2 = CO2

MgO + H2O = Mg(OH)2

Think of it this way:

2. The Decomposition reaction

1 becomes 2

CaCO3 = CaO + CO2

3. The Single Displacement reaction

Where 2 people break apart and 1 joins another

Fe + CuSO4 = FeSO4 + Cu

4. The Double Displacement reaction

2 people break up and both meet another

NaCl + AgNO3 = NaNO3 + AgCl

S&EP: USING MATHEMATICS

This week we used math to figure out the answers to the equations. We were still balancing them, just that we had to identify which type of reaction they were. I thought that balancing and identifying equations was important for chemistry work. Once you get the hang of it, it really is quite fun!

XCC: STRUCTURE AND FUNCTION

The different reactions really are just different bonds. In the double displacement, one atom pulls itself off from a structure and bonds with another atom{s} to create a different structure. That is cool and really important, since atoms do that all the time in the world around us.