Wednesday, April 13, 2011

Lentil: Acid-Base Chemistry

As one last activity for our study of Lentil we did some acid-base chemistry. Have you ever used cabbage juice as an indicator? It's very easy to do and it will allow you to test household items for pH- it indicates for both acids and bases. We thought it would be a fun exercise given that Lentil is all about a lemon!


First you cut the cabbage some and boil it in a pot. The juice left behind is the indicator!

I set up the experiment in an egg carton- I so wish my store hadn't switched to cardboard. These make convenient, disposable vessels for all sorts of science.

Our cabbage juice indicator- you can't see the deep purple color here...

J5 used a dropper to put the indicator in the liquid in his egg carton wells and he waited to see the change- which doesn't require much because it changes right away!

The results- the solution turns pink in the presence of an acid and green in the presence of a base. I had no bases on hand! We squeezed the orange into a well after he saw that squirting right on the orange didn't show much change.

I made this quick data sheet for him and he colored in the circles for what turned and what didn't. Then he dictated some narration to me about the experiment. I'll share the final result when I post his notebook pages.

All in all a very satisfying experience! Who doesn't love to use a pipette (we keep disposables on hand) and make things turn colors? We've started Peter Rabbit this week, but I'm looking forward to sharing his notebook pages. Stay tuned...

5 comments:

Brit said...

The fun math and science is worth coming here alone! along with all your other great ideas! We start Peter Rabbit next week a powerhouse week of Peter Rabbit and Earth day combined. I enjoy your notebook pages, It's always nice to have guide who has some experience under her belt. :)

Heather said...

Thank you Brit! So kind of you to visit!

Heather

Blossom said...

Neat! I think I've done something like this myself- but not with my kids. I'm a boring science teacher lol oh wait, that's not funny... ;)

Anonymous said...

Have you tried Science Experiments You Can Eat or More Science Experiments You Can Eat :D

Heather said...

We have not done experiment we can eat...yet.

Though I do recall dissecting squid in high school and frying it up afterward! It was grocery store squid...

haha