Monday, September 16, 2013

Acid or Base?

My son loves science experiments. He always has and I'm not surprised. Before I was his Mom/Teacher, I was a chemist. Science has always been a love of mine and it makes my heart happy to know that I've passed that on to him.

T is 7 years old and we are working on the Montessori 6-9 curriculum. I often add in experiments for us just because he is interested in them. The problem is that he thinks the experiment part is fun, he isn't interested in the reading of the instructions, writing and/or illustrating the results, or cleaning up afterwards. When he was smaller I let some of this slide since he has been struggling with writing. This year he has finally started writing at a pace that will allow us to actually write things down as we do them. This was his very first experiment where he did all of the recording of results.

This particular experiment I got from a science kit. I sometimes purchase ready made science kits when I find them cheap because it is a good way to get the "chemicals" (by chemicals I mean safe child friendly chemicals like baking soda, etc) and lab "glassware" (test tubes, beakers, etc but they are always plastic in these kits, although cheaper than buying them separate). I recently was able to buy a nice science kit with real lab glassware so we used that instead this time.

This is the kit we used for the experiment.

The experiment was to determine if common liquids around the house are acids or bases. First we took our holder full of test tubes around the house collecting liquids. Then we went back to our science lab and mixed up the pH indicator solution. The kit comes with a packet of Red Cabbage Juice Powder which is mixed with water. We added a couple of drops of the indicator solution to each test tube using a disposable pipette (which also came with the kit). As we did this, we took note of what color the liquid in the test tube changed to. Pink or red indicated the liquid was an acid, blue or green meant a base, if it was purple the liquid was neutral.


Our pH indicator solution

He found an acid (red)

This one is purple so its neutral

We ended up choosing mostly acids and a couple of neutrals but none of our chosen liquids turned out to be a base. I wanted T to know what it would look like if it were a base so we took out some baking soda (included in the kit) and dissolved it in a little water and then did the test on it.

Base (blue) Baking Soda and Acid (red) Vinegar


As we worked he filled in this page in his lab notebook. First he made the list of what was in each test tube. Then he drew himself with 7 test tubes and numbered them. As we worked he colored in the test tubes on his drawing with the appropriate colored pencil. When he finished the experiment he added the label acid or base next to each liquid on the list. He didn't have enough space on his list to add baking soda so he put it on top and numbered it 8.

Just to make it clear which liquids we worked with I will list them here, I know his spelling and penmanship isn't perfect yet.

1. Soap Neutral
2. Coke Acid
3. Hot Sauce Acid
4. Coffee Acid
5. Milk Neutral
6. Pickle Juice Acid
7. Saliva (yes he insisted on testing his spit) Neutral
8. Baking soda Base


3 comments:

  1. Hi, I just found you via My Boy's Teacher. We are homeschooling doing a fairly pure Montessori method,and I have a T who is 7yrs old too! I also have S who is just shy of 6yo and D who is just about 2 1/2yo. My T was also in a traditional Primary classroom for two years though because of his speech issues and his very late birthday, we had him repeat his third Primary year, so this year he is a first year lower el. I had thought we'd do a lot of third year primary stuff with S, since she had only one year of private montessori school but I am realizing because of her age that she needs some remediation and to move on to some more elementary lessons.
    Anyway, this is our first year at this homeschooling thing and I am enjoying the montessori elementary online community. This post about chemistry brought back memories, as I did quite a few years of chem I college before finally changing my major at the last minute!
    If you'd like to take a peek at what we are doing, I'm posting at www.montessorischoolathome.blogspot.com.
    Hope you are enjoying your break! Abbie and good luck on that turkey!

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    1. Thank you for your comment! I love that we have so much in common. I looked at your blog quickly and it looks great, I will take a closer look when I have a chance. Thanks for the luck with the turkey...we've now added a ham as well, Im going to need it

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  2. I just realized it was you who commented on my blog...sorry! I too forget to come back and read. This time you are in the feed reader, so I will not forget. :)

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