Mixture Separation Labs

First of all! Different ways you can separate mixtures:

1. Filtration - Using a filter to separate different parts of the mixture. You can separate smaller materials, like sugar, from large materials, such as sand or gravel.
2. Distillation - A way to separate mixtures based on their boiling points.
3. Chromatograph - The mixture (in this case ink) is dissolved in a fluid (water). The mixture is carried throughout another material (the filter). The different parts of the mixture travel at different speeds due to their density, so the mixture is separated.
4. Centrifugation - A process that uses a centrifuge, and separates mixtures based on centrifugal force and the densities of the components of the mixture.

Separation Lab


In this lab our mission was to take apart another team's mixture. The mixture we were given contained:

Iron Fillings - 7.38 grams
Marble Chips - 14.46 grams
Sand - 19.88 grams
Sugar - 38.70 grams
Calcium Chloride - 4.14 grams

To take this apart we:
1. Used a magnet to take out any iron fillings
2. We used filtration to filter out the sugar from the rest of the mixture
3. After the sugar was filtered out, we used filtration again to separate the marble chunks
We were able to do this all the first day. We cleaned up, left the remaining mixture and the separated elements on a designated spot on the counter, and confidently walked away.
4. Problem! The next day we found that our entire mixture and separated parts of the mixture, were sticky. We were not able to identify the calcium chloride that was in the original mixture. We weren't able to get any measurements on how many grams of it the mixture contained, and our entire work area was sticky.
5. We were going to filter out the remaining sugar from the dirt, but the entire mixture was stuck to the bottom of our beaker (thanks to the calcium chloride). So we though about using distillation to boil out the rest of the sugar, leaving us with only dirt.
However. . . We didn't have all the time in the world, and we really needed to get back and write up these blog posts. . . So we gave up. However, we used/played with the idea of some of the methods of separating a mixture (filtration & distiliation). We were able to pull apart most of our mixture, thereby determining that it was a mixture instead of a compound.



Chromatography Lab


With this lab we took circular filters and wrote/draw on them with markers. We then poked a hole in the middle of the paper, and placed a rolled of piece of paper in that hole. Once the paper was in the middle of the filter, we placed the entire thing in a petri dish filled with water, making sure that only the paper and not the filter touched the water. Then after a short wait, we saw. . . .

The water had come up through the rolled up paper, and had spread throughout the filter. The water had smeared the colors of the markers that we had drawn on the filter. With this, we were able to see the different colors being smeared different distances. We consistently found that blue was always on the outer most end of the filter, while yellow and red were usually much closer to their original spots. We even found that some colors didn't smear at all because they were from permanent  markers. This all means that the colors have different densities. The blue colors were lighter, and had smaller molecules, meaning that they were spread further by the water. The yellow colors were much denser, and had heavier molecules, meaning that they were not spread as far as the blue. 

You find all of this in this picture here:

The blue is right on the edge, with the red and yellow behind it. You can even see that the black, green, and purple colors came from permanent markers, as they were not effected at all.