Final Reflection

This year of chemistry has been very challenging but I've also learned a lot.  I'm not sure how I can use this knowledge for anything but blowing holes in the ceiling but that's not much of a concern.
I really enjoyed chemistry.  Even if I put off all the blogging until it was a daunting work load.
What I've learned in this high school chemistry class will carry me into other college sciences, (if I even have to take them).  I've thoroughly memorized lab procedures and I'm amazed at how simple loggerpro seems now.
This is my last blog and I don't know if it's much of a reflection but it's all I've got.
I hope future chemistry classes can find my blog even slightly helpful.  Or at the very least amusing.  Let me be a lesson to you all!!!!!

Beer's Law and Acids Lab

 Beer's Law- absorbence is proportional to the concentration of the solution.
Basically, light is absorbed by the solution.  It can be measured to figure out what the concentration of the solution is.
For this lab, we had mystery concentrations of nickel sulfate (NiSO4) in distilled water.  Our goal was to determine how much NiSO4 was in the solution.
To do this we used a Colorimeter, to measure how much light was absorbed by the solution, and hooked it up to a computer in order to graph the measurement of the solutions.  We measured our own concentrations of NiSO4 with distilled water and plotted them on the graph.  Then, we placed samples of the unknown concentrations in the Colorimeter and compared them against the measurements of our controlled, known, concentrations to figure out how much NiSO4 was in the unknown solution.

This is the graph of our controlled solutions.
The measurements we got for the unknown solutions were:
Unknown 1: .115 mol/L
Unknown 2: .365 mol/L
Unknown 3: .26 mol/L

I feel like I'm talking about pokemon.

Acid's Lab

Acid's are substances with a low pH value, meaning they give up H+ atoms.  Base solutions have a high pH number.  If you add an acid to water the acid gives up it's H+ and makes the water more acidic.  Adding a base takes up the H+ from the acid and levels out the water but it can happen kind of fast.
In class we added acid to water and added base in small integrals while we measured it with the computer much like we did with the Beer's Law lab.  Mr. Ludwig also added a chemical that would make the water change color when a base was added but wouldn't interfere with the acid mixture.  I can't remember what it was though...

We kept adding more base, in smaller intervals as the color stayed longer, until we leveled out the acid content of the water and eventually overpowered it with the base.  Water would have a pH content of 7, which is right in the middle of the pH scale and is considered neutral.  Right in the middle of that steep slope is where the 7 is and is the point of neutrality.
Graphing each point as we added more base formed a gradient as the two concentrations merged together.

Crystal Lab

The crystal lab is a complicated and unique process you've probably never heard of.  Like that underground band; Ink Metric.

Actually, the crystal lab is simple and kind of fun.  All you need for this lab is:

Distilled water, (hopefully from an old tank reminiscent of armageddon)  Aluminum Potassium Sulfate
A few beakers
Hot plate
String and stick
and some optional food coloring for fun

There is no real measuring to this lab.  Just add the sulfate to around 50-100ml of distilled water in a beaker and stir on the hot plate.  What I did was turn the hot plate all the way up and completely dissolve the sulfate in the hot water and then add a bit more.  I stopped when I could see the sulfate moving at the bottom of the beaker, like that clear medicine you have to put in fish tanks sometimes.
I let my super saturated solution cool for a few minutes before I added some red food coloring, just because.  Then, I left it alone over night and came out with a single, really cool, really big, seed crystal.

Then, I took the seed crystal and tied it to a stick.  I repeated the distilled water and sulfate process in a much bigger beaker and used a lot more sulfate.  Then, I suspended the seed crystal inside the water to let the sulfate cling to it and crystalize over it as the solution cooled and the sulfate crystalized.  I ended up with a few more perfect seed crystals at the bottom of my beaker and left them around for my classmates to use if they didn't want to wait for a seed crystal or were unable to form a good one to use.  They're blue because I added blue coloring to the red to try to make purple.

This is the crystal my solution produced.  I'm so proud.  It has such nice, even angles.  The crystal for mine ended up forming in triangles.  The entire thing looks like it was put together by Zelda.  I put this crystal up on the ceiling with the other awesome crystals and made another one from another of my seed crystals to take home.

Hopefully you can reproduce this on your own at home.  You could try using substances like sugar and salt to make crystals.  Then, you could eat your crystal and it'd be okay to lick it. >.>

Radioactive Decay Article Summary

Image found here.

According to Brian Thomas' article, radioactive elements do not decay at steady, predictable rates.  Several laboratories and universities found that some decay rates, specifically of silicon-32, altered with the seasons.  After the matter was looked into more in depth it was found that solar neutrinos from the sun are the most probable cause for this fluctuating decay rate.  Though little else is known about the why's and how's of this new puzzle it's a certain fact that this discovery rather shakes the foundations of rock dating.  If the decay rates of these radioactive isotopes can be effected by solar flares how are we able to tell just exactly how old something is?  Food for thought.



P.S. I've made an entire prezi and tumblr post for radioactive decay.  Go check it out!

Evaporation Lab

Evaporation Lab

Armed with but a couple of temperature probes and some suspicious clear carbon compounds we ventured into the world of the unknown.  We took two probes and wrapped the ends in filter paper to soak up the chemicals we were testing.  We tested two substances at a time and dipped them in first the methanol and ethanol, then the propanol and butanol, and finally the hexane and heptane.  We taped the two probes over the edge of the counter so they could evaporate freely and without interference.  Once they were completely evaporated we recorded the readings.  After the initial readings of the methanol and ethanol and based on the number of carbons we guessed that the temperatures of the next four would be higher because of the greater number of carbons.  We were fairly right to assume this.

 This pre-lab chart shows the formulas of the substances we used and is what we based our estimations on.  Because we were able to count how many carbons were in each substance we were able to determine whether the temperature went up or down with the number of carbons and whether or not the presence of a hydrogen bond had any effect on the temperatures.

This is the table of our actual and predicted measurements of the probes.  As you can see our guesses were pretty close because we had already determined that the temperature rose from methanol to ethanol.  The last two are much more off because we hadn't determined quite what sort of effect the hydrogen bond had.  Apparently, the lack of a hydrogen bond sort of starts the pattern over.

In this image the green line represents the methanol and the red line represents the ethanol.  According to this, the more carbons present in the compound, the quicker the temperature change is.

In this image Propanol is the red line and butanol is the green one.  While they're pretty close the higher carbon wins out again and creates the most dramatic change.

Here, hextane is the red line and heptane is the green line.  Once again the greater carbon had a more dramatic change. Don't be alarmed by the rise in the temperature of the probe with the heptane.  It just took hextane a lot longer to level out than heptane.  We believe this was simply because they aren't as close together as the previous ones were carbon-wise as our teacher was out of the substance we were originally supposed to use.

Whoops, I misread my own tables the first time I wrote this conclusion.  I'll try again.  As my table at the top shows, the shift in temperature becomes smaller as the amount of carbons in the molecular sequences increases.  However, when there is no hydrogen bond as with heptane and hextane, the temperature shift grows with the amount of carbons.  But, fewer carbons tends to mean a greater shift in temperature from the beginning to completion of evaporation.

3rd Quarter Reflection

I'm not gonna lie.
I'm perfect.
But when I'm not perfect I have things to work on.
This quarter was filled with tons of math, data, experiments, and procrastination.  I'm so good at procrastinating.
Some of the math and calculation work this quarter was pretty difficult for me to wrap my head around.  Math isn't my favorite subject and I'm not exactly scientifically minded so when the two mix I get annoyed and ignore it a lot.  As I'm planning to be a Liberal Arts major (hahahahahaha!) I don't see my disregard for Empirical Formulas to be that much of a problem.
Of course, as a senior I ought to buckle down and set my priorities straight.  Which brings me to the procrastination.  It's a lot harder to turn in assignments when they're entirely dependent on you.  By this I mean, when your teacher isn't asking for a written analysis and procedure after every single experiment it can be hard to motivate yourself to put that information up in a blog.  It's so easy to leave that for the last minute.  Like I've been doing all year.  But it's also not a good idea and it's hard to get the best grade I can when I'm rushing everything.  Obviously.  So I want to be better, obviously.  This new quarter is dedicated to not procrastinating.  Just because I can get everything done in the nick of time doesn't mean I should.  Even if it is science. As much as the beauty of tumblr constantly calls to me I must get the sciency stuff over with as quickly as possible, like ripping off a band-aid.
I'm also going to take more pictures of labs and stuff.  Looking at my experiments post is depressing and it'd be fun to have lots of pictures to go with my labs.  I can change!!!
4th quarter is going to be a lot better.  Well, of course it is.  It's my last quarter of high school!! :D

Labs and stuff!

We do a ton of labs in this class, which is awesome and good and delightful, but I'm too lazy to make individual posts for each.  And apparently too lazy to take pictures of the labs.  Which is something that I constantly regret...


The Unknown Element Lab


In this lab we were given a chart with moles of each beaker on it.  The beakers had A-J labels on them.  We weighed the beakers one by one to determine the amount of grams, taking into account of course the weight of the beakers, and divided that amount by the number of moles corresponding to the letter on the beaker.  It was really fun because it was easy.

The Burnt Popcorn Lab

Coat the bottom of a beaker with enough vegetable oil to just barely cover the surface.
Make a cover of aluminum for the beaker and then weigh it. (190.5g)
Add a few kernals, just one layer of kernals on the oil, and weigh it again. (207.65g)
Now situate that baby over a bunsen burner and let. It. Burn.  We did.  Pretty sure some of the popcorn caught fire too but that's how we roll.  Once all the popcorn is popped weigh it again. (205g)
Now, take the initial weight of the kernals by subtracting 190.5 from 207.65.  This gives you 17.15g.  Then, subtract 190.5 from 205 to get 14.5g, this is the weight of the popped kernal.
Divide 14.4 by 17.15 and you get the percent of the weight of the kernal without the water, 84%.  So, the rest of that percentage must be water.  Kernals of popcorn are about 16% water.  Apparently popcorn pops because of the water.  When the water heats up it bursts the kernal open and voila!
We weren't allowed to eat the popcorn we made, not because it was burned but because we used a beaker that was once a bacterial pond water growth lab.  But that didn't bother us, it's a lot easier to cook unburnt popcorn with the ancient microwave in the inner hex.

Hydrates and Predictions

You should see my notes for these labs. They're hilarious!  If I didn't know my head I'd have no idea what these stupid scribbles are.
Anyway!
The point of this lab was to figure out what percent of CuSO4x5H2O is water.
We made our predictions beforehand.
Using 5.25 g of the compound we guessed that approx. 1.5 g of it was water.
We heated the Copper Sulfate in a test tube over a bunsen burner until it ceased all blueness.  When that cooled we measured the copper sulfate again and found that we now had 3.45.  So, 1.8g of the copper sulfate stuff was water, that's about 35%.  We were pretty close but that was pure luck.  Compounds like CuSO4x5H2O can be calculated before hand to decide what percent would be water by adding the moles of all the elements together and tabling that with the grams of the compound we'd use.  It saves a lot of time if you're not as lucky as we are.

Baking Soda Lab


The goal of this lab was to get the baking soda to dissolve completely in the vinegar so that there was no longer a reaction.  Usually this takes a lot of guess work on the measurement of baking soda to use so that it's no longer reactive.  My group took the measurements of our supplies and calculated the perfect amount of baking soda to use before we even started so that we didn't have to spend time doing any guess work.  But the cat got my data for this lab so I don't have the exact numbers.  Not that they were important unless you need the perfect ratio of vinegar to baking soda for something practical.
All we did was take the amount of vinegar and cross multiply with an x amount of baking soda.  It was pretty basic algebra, a part of algebra that hasn't been replaced by my obviously practical need to be a calculus whiz.  The x amount of baking soda was the amount we needed to achieve that 1:1 ratio.  Worked like a dream.

The Mr. Ludwig's Retirement Fund Lab

Or the silver copper replacement lab.
This lab took a couple of days to complete.
We took 30cm of copper (3.49g) and coiled the end loosely so it would fit inside a tiny test tube.  We added distilled water and 1g of silver nitrate to the beaker then dropped in the copper and sealed it.  The copper dulled instantly and shaking the tube lightly made the copper turn dark as the silver took hold.  Then we just left it alone for a day.  Or over the weekend?  I can't remember, I was bed ridden for a few days.
Apparently my partner had to spray the silver off of the copper with distilled water and into a funnel made of filter paper.  That sat for a day as well to let the water filter through completely.  After this we weighed the silver and copper again.  The .35g of silver went to Mr. Ludwig's Retirement Fund, he'll be set.  And the 3.193g of copper went in the trash or something.  All we needed were the numbers.
Our stoichometrically predicted number of how much silver would be produced from this lab was .65g.  This was quite wrong obviously so perhaps we messed up the math a bit.  I'd rather blame the method of silver extraction though.  When shaking the silver from the filter paper the paper was quite gray so obviously that didn't come away clean and this is most likely why our numbers didn't match up.  I like that answer a lot better than wrong math.

So that's it for all the labs!  Sorry there aren't more pictures.  I'll remember to take lots of pictures for all the labs next quarter.