martinzoo

Thursday = Science Day

Today we learned ( ** note - I say we, because frankly, I learn right along with GB) how to separate mixtures in our Chemistry course.

There are three ways to separate mixtures according to the Real Science 4 Kids text book. First, through FILTRATION. Filtration can be used to separate two or more things of different sizes.

Experiment: Separating water from sugar grains

We used two types of equipment to filter the water. A colander, which provides big holes or “pores” for the water to pour through, and a coffee filter which has tiny holes. Now, you can be like GB and think that a coffee filter has no holes, but when we pulled out our new, spiffy microscope, I was able to show him the holes in the coffee filter.

Looks a little like the moon, doesn’t it? But that’s the filter under the microscope.

Then GB poured sugar into the water and stirred it up.

All mixed………. or so you think.

Then he poured the sugar/water mixture through the colander. Surprise, surprise, it all went through, even the sugar. So the holes on the colander were too big to separate the sugar from the water.

See all the sugar in the bottom of the bowl?

Next we put the coffee filter in the colander. It’s too whimpy to stand by itself. Then we poured the sugar/water mixture into the filter.

As you can see, the coffee filter was able to separate the sugar grains from the water.

Our second method of separating mixtures was through EVAPORATION. If the items that need to be separated are of equal, or nearly equal size, we can use evaporation to separate them.

Experiment - Separating salt from water using evaporation.

First we put water into a saucepan. Then, we poured in some salt. No measurements this time, we just dumped in some of each. When the water has evaporated, only the salt will be left in the pan.

Now, other folks may have oodles of time to wait for the water to evaporate from this pan of water/salt, but I clearly don’t have the patience for that. So, I added a bit of heat to speed this puppy up.

After about 5 minutes, the water was gone, and we were left with some nice chunky salt mounds.

See! Scoopable!

The third method of separating molecules can be done with CHROMATOGRAPHY.  Chromatography relies on the fact that different molecules stick to each other in different ways. You can use this process to separate colored compounds.

We did do an experiment to show the chromatography process, but it’s still going on. So you’ll have to tune in tomorrow to see our results.