Category Archives: Chemistry

The Chemistry of Autumn Color

I have always loved this time of year, and now that I live in the Appalachian Mountains I love it even more! I thought we might break into our regularly scheduled chemistry lessons this week with a little seasonal chemistry.

We are going to watch this video on why leaves change color, and then read through this short webpage outlining the chemistry behind it.

We may even do this experiment (4th and 5th paragraph) to find the hidden color in a leaf that hasn’t changed yet, and preserve a few for our nature study table.

Of course, we’ll top it off by journalling in our Chemistry Notebook.

What Chemistry Principles Are We Covering

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I put together a list of the chemistry principles we are covering while completing our Living Chemistry course this year, and uploaded it as a PDF for you to check out. You could consider this a scope and sequence, but the reality is that we are doing it backwards. In other words, instead of covering the list sequentially, we are letting our spine text lead us to each principle.

I came up with this list by looking at several scope and sequences for high school chemistry, as well as the table of contents of several chemistry textbooks, to compare what we were learning to what we would be learning if we did a traditional textbook. I was happy, but not surprised, to see that we are really covering everything they are – just in a different way. I would like to think that our way is much better!

Blowing Up Balloons Chemically Experiment

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In this experiment the objective is to determine what observable factors are changed in a chemical reaction and what factors remain constant.

Chemicals Used:
Part one calls for 50 ml hydrochloric acid (you will need to buy 2 of the linked to product,) and 8 grams of zinc.

You can also buy the Hydrochloric acid at someplace like lab or at a commercial cleaning supply company under the name “muriatic acid”, but you want it diluted to 3 M for this lab. I chose to buy it from lab.

Part two calls for 50 ml acetic acid (vinegar) and sodium bicarbonate (baking soda).

I bought these two items, only because I didn’t know that I had them in my pantry!

Equipment Used:
250 ml flask
Balloons
Balance – We didn’t have a balance, so we went on without it, but because we want to consider the Law of Conservation of Mass, it would have been a valuable tool to have.

Safety Considerations:
You are using acid this week so use proper safety precautions for hydrochloric acid! Please be sure to use goggles, gloves, and possibly some protective clothing.

You should do part one of this experiment outside.

Things Considered:
In an exothermic reaction energy is being released by the reaction, therefore the system becomes warmer.
In an endothermic reaction energy is being used by the reaction, so the system becomes cooler.

Watch the Experiments:
Here is a video of part one being demonstrated.

What Happened?
Here is an explanation of what happened in part one (that’s hydrogen gas in your balloon – be careful,) and part two (it’s just carbon dioxide in this balloon – your plants will like it.)