Week 3: Hot Pots and Lewis Dots

This week was kind of split into two parts. The first part was focused on the test we took Wednesday. The second part we started on some new material, which I greatly appreciated.
To be blunt, I did very poorly on the test. In hindsight, I should've practiced more for the short response than I did for the multiple choice, because even if I didn't have a calculator I felt I knew the concepts well enough. But for the short response I had severe technical difficulties. This is a problem that I need to work hard to address. But I thought the Hot Pot quizzes were very helpful with the multiple choice section. I'd like to have more of those before tests in the future.
I must admit that I jumped for joy when Dr. Finnan said that there wouldn't really be any math on the next test.
For the remainder of the week, we began doing Lewis dot diagrams which I think are really cute and fun to draw. These are diagrams that show how many valence electrons any given atom has and you can put them together to form molecules. Here is the diagram for water, which I think looks rather like two tie fighters circling the Death Star.

This shows that one atom of oxygen has 6 valence electrons and can thus form bonds with two hydrogen atoms (which have 1 valence electron each). The dots stand for valence electrons. The dashes that you can see are just an easier way to write two dots shared between a pair of atoms. 

Another new thing we discussed was the "octet rule" which basically states that each atom's greatest life ambition is to have 8 valence electrons and will drop or gain electrons in order to do so. This doesn't apply to all elements though, such as hydrogen, which follows a similar "duet rule". 

I think the most confusing thing for most people right now is probably understanding the difference between valence electrons and total electrons. I imagine that in the next few days this will no longer be a problem. 

Rumor has it that we will have a lab next week, which I am incredibly excited for given how entertaining the last one was. I'll leave you all with your science meme of the week. 

Week 2: Let's Do Some Math (!)

Coming off of last week, when we did this really fun lab about molarity, this week was pretty mellow. The majority of it was spent doing worksheets at home and POGILs during class. I'd say that the main theme of this week was "calculations". We did a billion more stoichiometry worksheets. We also started in on some empirical formulas, which I think are much more tolerable than the straight stoich worksheets.
This week I feel like I really gained a better understanding of how to use the different formulas, though.  The repetition of them what with the worksheets and the in-class work kind of forced me to sit down and really work through and get it locked down.
All the stoichiometry did kind of get my brain back into math-mode, which is new since I don't have a math class this trimester. I wonder how much of chemistry is going to be what I call "straight math"? Only time will tell.
For me, the fun (ha ha) part of the week was starting on the empirical formulas. I really enjoy learning new concepts, especially when we'd been battling stoich for the second week now. Here's a cute graphic I found that I think accurately explains the main idea of empirical formulas:

I really like this image because often times it's easier to get the idea of certain things with non-chemistry analogies (like the egg POGIL we did in week 1). It can be tempting at first to just copy down the work from the lectures or the whiteboards, but this isn't a good idea. Later on, having a solid knowledge of the actual idea comes in handy. 

I can't help but wonder how much I'll have to use this stuff as the course goes on. Part of me hopes that it'll be gone soon but I also think that it's just kind of a basic skill I'll have to get really good at. 

I guess that means the hard stuff is yet to come! What fun! Next week I really hope we have a lab or something because it makes the blog post a lot more interesting. 

For a closing thought, here's a lovely picture of the cherished Chemistry Cat that pretty much sums up my feelings of this week. 

Week One: Blue Gatorade and Quail Eggs

In my mind, this week was the first real week of chem. Not only did I start to feel the full force of the homework load, we also got to do some more interesting things in class than review and straight numbers. To start out the week, we learned about molarity and all that molarity entails. This includes things like learning to use certain equations and how to solve for concentration in any given situation.  For me as an individual, I feel very confident about the big ideas of molarity but I get hung up on the actual calculations and how to use units in each situation. I think that as the course progresses and we do more things like this I'll find it easier and more understandable. I also am thinking of doing some practice on my own for this.

I also found this awfully catchy little tune to remind myself what a mole really is. Enjoy!
The other major thing we did this week was our first lab! During the lab we had to dilute a blue #1 dye  stock solution with water and measure the absorbency with a colorimeter. I wanted to know more about how colorimeters worked, so I looked for a diagram that would be helpful.

This helped me understand the process a little bit clearer than mud. Anyhow, we also measured the absorbency of blue Gatorade/Powerade. Afterwards, we calculated the concentration of blue #1 dye in each of these solutions. For me, having a real-life experience gave me a better understanding of how to do these things. I look forward to the labs that we may do in the future, as I find them the most rewarding part of all the hard work we do.