Wednesday, October 20, 2010

A Fun, Fantastic, and Fulfilling Day with PAPER CHROMATOGRAPHY!

Aren't lab days just the BEST things ever? Scroll into class in a relaxed manner, slouch deep into your chair, and start mixing highly toxic, flammable, biohazardous, oxidizing, explosive, corrosive, (and did I mention toxic?) substances together without bothering with lab goggles. Who needs to be careful, right? The worst that could happen is the poisonous fumes cause everyone's lungs to collapse and the entire class huddles together to die a slow painful death.

Ooooh. Sorry. Did I cross the line? Okay, I'll stop. :S


On Tuesday, October 19th, 2010. We performed Lab 3B out of Essential Experiments for Chemistry. This is page 32-37 of the book.

The idea of the lab was to discover the components and Front Ratio (Rf) of various solutes (food coloring) with a solvent (water). We were to do this through paper chromatography, of course.

I hope that you all remember what was done during the lab. For example, the observations you made, the type of data collected, and the calculations made.

Recall that we drew a pencil line across each of our three 22cm strips of chromatography paper, 4 cm from the end, and cut it so that the strip has a pointed tip.

After putting a drop of sample onto the drawn line of the strip, we placed it into a test tube with 2cm of water. After 20 minutes of waiting, we measured the distance between the length travelled by the solute (d1) by the solvent (d2) from the pencil line. (Measurements were done using a ruler, measuring in cm) We then calculated the component:solvent front ratio (Rf).

The way to calculate the front ratio was simply to divide the distance that the solute travelled by the distance that the solvent traveled. Your result (aka. your Front Ratio, Rf) should be between 0 to 1. This "rule" can be found in your lab book!

Rf = d1/d2

Remember all the observations you saw while the fronts moved. Certain colors of the solute seperated into multiple colors, such as blue, yellow, and red! However, some solutes, such as the one with yellow coloring- did not seperate! It just remained the same color except expanded. This is because there are no colors that mix together to create yellow. But, yellow can be found as a component, because it is used in mixing to create new colors.

This lab should've helped you understand a very accurate form of seperation, which again, is called paper chromatography!

Thank you for reading our entry about paper chromatography. :) -MJH

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