Wednesday, January 26, 2011

A big clean mess

My class has been begging to do cabbage juice experiments ever since we did the project a week ago.  However, I can't really take the smell of cabbage anymore.  It literally has always turned my stomach.  I think it is because I grew up in a rural area and so when I smell cabbage I think of the rotting cabbage field smell?  Anyway, on to more important things.  
Since cabbage juice is out for at least 3 months (and hopefully they will stop asking by then), I thought a little free experimenting was in order.  So today I loaded up our table with acids and bases:  Lemons (cut in half), medium grape fruits (cut in quarters), baking soda, alka seltzer tablets, dish soap, and water. With these things, surely any child can create a potion to suit their fancy, and as a matter of fact they made not one, but at least 5 each.  

Lemons are actually the most acidic citrus fruit followed by limes and the grapefruit.  The beautiful thing about the grapefruit is that they are so easy to squeeze and have a ton of juice in them. The reason for giving them the actual fruit is that, to me, it makes it more real when they actually see it coming out of the fruit.  Squeezing also slows them down, so in theory they are able to take in more of what is happening, and also is a great motor exercise; They really have to use those little hand muscles on the lemons!
They went through many grapefruit and lemons in this experiment. 

I had assumed that they would be more likely to use lemons, since they would yield a greater reaction but they seemed to prefer the grapefruit for two reasons. First, the grapefruit (as I said earlier) were easier to squeeze juice from, and second, like most 4 year olds they have small "boo-boos" on their hands and they found that the grapefruit didn't sting their boo-boos like the lemon did.  

In any case, they were able to create a wide variety of reactions (and "potions").  

This was probably one of the best reactions we had: a little baking soda, some soap and a big squeeze of lemon, it eventually overflowed the container.

I think this one had three or four alka seltzer, water, soap, baking soda, and maybe a pinch of grapefruit juice
One little girl was working on a cup that was not really reacting beyond a few bubbles no matter how many alka seltzer tablets she put in.  You can see here that when she dumped it on a top the alka seltzer were still whole, protected in a layer of baking soda and soap.  (In this mixture there was only water, dish soap, baking soda and alka seltzer).

You can see that once she added lemon juice several things began to happen: the baking soda bubbled, the alka seltzer began to dissolve, and swirling patterns emerged in the liquid resulting from the reactions.

One child put an alka seltzer tablet on the grapefruit and on the lemon and then gave them each a little squeeze.  The one on the lemon dissolved first, as you might imagine.  

After they had successfully used all available cups and containers  and neutralized almost everything, they were content to just mix their potions with each other, pouring them back and forth and adding water and baking soda, (the only things left from the 2 dozen lemons and dozen grapefruit), stirring, and pouring some more.  To get water, by the way, they used turkey basters instead of pipettes- allowing them to use more at once.  The basters also became instrumental in transferring liquids between cups for them and doubled as stirring utensils.  I got this idea from somebody's   blog but I cannot remember to whom the blog belonged, so if it belonged to you- let me know and I will link you to this entry.  

They really enjoyed this experiment, (although maybe not quite as much as cabbage juice).  One child did ask me if they could have the vinegar (remembering the power of the vinegar from the last experiment, no doubt).  However, because vinegar is much better suited for outdoors science projects, and because we were out of vinegar thanks to the cabbage project, they made do with the lemon juice.  

**Another really awesome thing about this project is that between the lemon, baking soda and soap, it makes any room smell amazing! It is a welcome change from cabbage juice.  Those three ingredients are also great for cleaning, so the table and floor that the project is on will clean up beautifully- it actually took  a couple of stains off the table that ordinarily I would use Commet for when the kids weren't around.  :-)

1 comment:

  1. It did smell delish in there when I came in to get her coat! M'mm!