Semester Reflection of Destruction!

This semester was fun.  I've had a blast in 5th hour chemistry, I'm gonna miss it!
I think I officially suck at the periodic table.  It's so hard to keep up with how many electrons go where and I keep forgetting how many s orbitals come before a p orbital as well as when you're supposed to start back at the s orbital again.  That's part of what killed me on my final test.  Ugh!  Hopefully I never have to do that again.
I'm very happy with how 'pro' I am at chemical equations and such.  I got most of the questions regarding chemical equations right on the test and it was fantastic.  Reaction types and laws of mass are so much more fun than the periodic table, as much as I love it.  I'll be very glad to move on to molecules.  I love molecules.  I might not be very good at the periodic table but I'll be happy to draw out sodium chloride. Hopefully I'll stop getting B's on the tests next semester.  I want A's!  I know this is standard based grading but I'm still addicted to the letter grades and percentages on my tests.

Yay end of semester!!!!! (From crunchyroll)

Reaction Types of Doom!!!

Ahh we're finally into my favorite part of chemistry!  I love molecules and chemical equations.  They're so much fun to balance.  I loved balancing equations in intro to chemistry but I really need a refresher on how to do it.  I took the class freshman year and, alas, I have forgotten how to do it.  I just like it.

Learning the reaction types will do for now!

Synthesis:                    A+B→AB
Decomposition:           AB→A+B
Single Replacement:    A+BC→B+AC
Double Replacement:  AB+CD→CB+AD
Combustion:               Fuel+O2→H2O+CO2

So reaction types are easy to remember and are quite obvious.  We did a series of little labs, seven in total, where we mixed a couple of things together or added heat to something and observed the reaction.  Nikki and I wrote down the equation for what happened and what we saw happening and labelled the reaction as one of the types of reactions.  I'm not going to write up all the labs because there were seven of them and I don't feel like writing them up.  Besides that I probably got them all wrong.  It's a lot different to name a reaction or equation from what you see verses what you can do on paper with other reactions.  I might not be able to perfectly translate my skills with this stuff to real world application but I still have fun doing it on worksheets.

Metal Reaction Labby Thingy

Picture taken from my iPad.

To the left you'll see a photograph.  This might be meaningless to you but I shall try to shed some light upon the situation.
In this lab we tested the reactivity of metals with different substances.  We tested zinc, magnesium, and copper, shown respectively in the photograph.  In the first row we placed about 8 drops of copper nitrate.  The second row received magnesium nitrate.  The third row contains zinc nitrate.  And the final row contains silver nitrate.
All of the metals reacted with silver nitrate.  Silver nitrate was the only substance that the copper reacted with.  The magnesium reacted with the copper nitrate as well as the silver nitrate.  And, as you can see, zinc reacted only with silver nitrate and copper nitrate.
It's interesting that copper only reacted with silver nitrate.  What's also interesting is that the zinc reacted to the copper nitrate but the copper didn't react to the zinc nitrate.  I have no explanation for this.  I didn't really focus past, oh hey the metal turned black!  I'm sure the reasons will be clearer in the future.

Another Lab! It's.........IONIC COMPOUNDS!

For the conductivity lab we used:
25 cm Magnesium Ribbon
A tiny crucible
A ring stand
Clay Triangle
Bunsen Burner
Conductivity Tester
Distilled water
Beaker
Balance

The bunsen burner was set up underneath the clay triangle and ring stand.  We weighed the magnesium and crucible separately on the balance and then crumpled the magnesium into a loose ball, put it into the crucible, and weighed them together.  We placed the crucible just over the blue part of the flame on the bunsen burner until the magnesium became so hot it ignited like those flashing fireworks.  Once it was cool enough we measured the crucible with the burned magnesium again.  Once we weighed it and found that the magnesium and crucible had gone down slightly in weight we dumped the burnt magnesium into a beaker and added distilled water.  When we checked the conductivity with our conductivity tester the light lit up at about a 5 in accordance with our last conductivity lab scale, putting it with antacid and light corn syrup conductivity wise.
Nikki made this awesome graph to show what happened.

Apparently the magnesium was supposed to gain mass.  We saw that it lost it, according to its weight.  Alas, we were impatient and our data was tampered with because we didn't allow the crucible enough time to cool down before we weighed it again.  Better luck next time.
The fact that the magnesium product weighs more is the main concern here.  When heat is added to the magnesium it causes a chemical reaction that apparently allows the magnesium to gain more mass.  The law of conservation of mass states that this can't be true.  So what happened?  The only possible explanation is that the magnesium, when heated, was able to combine with the oxygen in the air around it.  That's right, we weren't just heating up the magnesium, but also the air inside the crucible.  Those joined together and rather oxidized the magnesium.  That makes sense in my head but I might be mistaken.

The Conductivity Lab

In the conductivity lab we stuck a conductivity tester in different mixtures of water and either calcium chloride, antacid, potassium chloride, light corn syrup, molasses, or cheerios.  Water conducts too of course so we tested water alone and used the brightness of the light on the conductivity tester as 0.  The products we tested were based on a scale of 0-10 based on brightness of the light.

Calcium chloride was the brightest of the group of mixtures.  We gave it a ten.  Cheerios were the least conductive and there was really no change in the light.  

So what does this graph mean?  Different substances have different levels of conductivity in water.  The charge produced from more acetic substances like calcium chloride and potassium chloride is greater than less acetic substances like antacid, corn syrup, and the others.  The qualities that make substances like calcium chloride sting when they get into a cut create a better environment for conducting electricity.

And no, Mr. Ludwig, I totally swear I didn't get any calcium chloride into the cuts on my hands from physics.  Not that I got any cuts from physics. 0-0