Day 5: Another Lab Day!! Diffusion and Osmosis part 2 (special guest appearance by Benedict!)

Two lab days in a row!!! And this time we were dealing with fancy things like NaOH and base phenol and things like that.

Our entire lab was basically about cell membranes. Half the class worked with NaOH and the other half worked with KI. My fabulous lab partner, Michelle and I claimed the small cubical shapes that was NaOH (KI was cut into cubical shapes too but NaOH is better!)

While our teacher was setting up the various cubical pieces of NaOH and KI, the class began working on the second part of our lab, which was the semi-permeableness (is that a word?) of a cell membrane. Michelle and I filled a dialysis tube with starch and put the tube in a cub of tap water. Before closing the tube, we put glucose indicators in the tube and the water to see where the glucose was before we dumped it in water.

 The dark tip indicated that there is starch in a substance, which was a good thing because that's the one we put in the glucose starch solution. The other one is the one we put in the water, and that one didn't change color, so no glucose!!

So we tied up the tube and dunked it in water and proceeded onto the next part of the lab.

After obtaining our pieces of NaOH, we measured the sides in order to get the surface area and volume of the three cubical shapes. Then we put each of the pieces into a beaker and poured base phenol onto it. The change was pretty epic.

 Before and after:

Now, base phenol is a clear substance. When it reacted with the NaOH, hot pink burst from within the magical properties and created PRETTY COLORS!!!! (or if you want to be a killjoy, you can say the chemical reaction between the base phenol and the NaOH was the reason things turned into a violent shade of pink.)

So as we leave the NaOH to soak up the pink, we turn our attention back to the glucose in the water. 

We put a couple drops of iodine in the water and then took a sample of that water and put it into a test tube.

Now the moment you've been waiting for. This is where dear Benedict comes into play. 

We added a couple drops of benedicts into the test tube along with the iodine water---wait, you what did you say?

You thought I mean this Benedict?

Hahahaha, oh if only....

Nah, I'm not talking about Benedict Cumberbatch. I'm talking about this: benedicts!

So anyways, we added a couple drops to the water and heated it up. Now, before we heated it up, the color was a bluish color. After, it looked something like this

Bright orange!!! And that proved that there was glucose in the water. Because the glucose molecules in the solution were able to pass through the membrane. 

We then took out the dialysis tube from the water and noticed that it turned into a really dark blue, which meant that the starch stayed in the tube because the starch molecules were too large to pass through the membrane into the water. Also, the iodine must have diffused through the membrane because the molecules were small enough. 

So part one of the lab: complete!

Onto the end of part two!

We took out our now a grotesque shade of pink NaOH cubes and cut them in half to see how far the solution had diffused through the cube. This one was our largest cube. Each cube had the solution 0.5 cm into the cube. 

And thus concluded our lab on Diffusion and Osmosis.

Until next time :)