Archive for the ‘chemistry’ Category

Sick Day (With Yeast!)

What do you do while stuck at home with a sick three-year-old? Bake bread! Well, okay, I did the baking, but Z requested a science experiment. Who am I to pass that by?

Because he so loved the baking soda and vinegar stuff, I gave Z some yeast, water, sugar, a funnel, cups, and balloons. First, we took a look at what yeast does with cold, warm, and hot water. IMG_0833

Then, he (mostly carefully) scooped some yeast and sugar into balloons, and added different temperatures of water to each. Check this out! The green balloon is cold, pink is warm, red is hot. In Z’s words, pink wins! Yeast must like warm water. (The blue balloon is a whole bunch of everything.)
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This was more interesting to me. About two hours later:
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Green and pink are now basically the same size. The red (hot water) balloon must have killed a lot of the yeast.

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Baby’s First Experiment

This is the first time I’ve tried an “organized” experiment with Z, rather than noticing some happenstance thing. Z is 3 years old (hence the quotes around “organized”), and received this little “experiment set” for his birthday, so what better to do with it than to mix some vinegar and baking soda.

The initial bubbles were pretty fun, but afterward was more interesting for me.

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Me: It stopped bubbling! How can you make it bubble again?
Z: More vinegar!
experiment bubbles
Me: It stopped again. How can you make it bubble again?
Z: More vinegar!!
nothing happens
Me: Huh. That didn’t do much. What else can you do?
Z: More baking soda!
bubbles over the top

Then, it kinda turned into a free-for-all (a.k.a., what any three-year-old does, as well as good experimenters). He started pouring everything together.

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Z: I need more baking soda!
Me: How do you know?
Z: It stopped again.
nothing happens
Me: Now what?
Z: More vinegar!

The test tubes are full of water, post-iterations.
Me: Let me pour some liquid off. This is called “decanting”.
Z: Decanting? Okay.
Me: See all of the stuff at the bottom? Does it look more like vinegar or more like baking soda?
Z: Baking soda!
Me: So what should you add to it?
Z: Vinegar!
Me: Why?
Z: I dunno!
bubble bubble

Why this is cool: Z is trying (a very limited number of) reactions on his own. He knows that both baking soda and vinegar are needed to make, but couldn’t (or wouldn’t) verbalize it for me. The next day, I brought out baking soda and baking powder (and vinegar and water), but he really just wanted to pour everything together again rather than stop and compare. He did, however, leave the baking powder alone, once he saw that it made fewer bubbles than baking soda, meaning he’s taking some mental notes about getting more of what he wants.

I did, however, forget to have him say, “sodium bicarbonate” and “acetic acid”. What kind of a chemist am I?