Upcoming Test

I hate Monday tests. Or at least extremely dislike. It means I have to study over the weekend or at least look over the materials and I'm not a huge fan of that, rather do that on the weekdays.

Over all I think I'm gonna gonna do pretty well, at least on the first half of the unit. I ended up getting 15 out of 17 correct on the test, or a 88%. I'm still kind of confused at the point of the both empirical and molecular formulas, and when I think upon it further, the latter of the two makes more sense. Why would there be a formula which isn't even the actual formula of the compound (empirical)? Found some more information upon both of these formulas here.

Empirical and Molecular Formula

The empirical formula is the simplest formula for a compound. This is different form the molecular formula, which is based of the actual number of atoms in a compound. Now I don't really understand why there are two types of formulas if the both tell you basically the same thing. I would think that all formulas would be reduced down to their simplest form anyways.

This chart shows the difference, and sometime there's none. The way to find the empirical formula from just knowing the elements present and the percent abundance is kind of confusing but manageable. The math behind it can be found here.

Post Quiz Thoughts

Just had the weekly quiz today, and oh my. It really wasn't that terrible, but the first question made me think my teacher had it in for me. It was one of those multiple step problems and in hindsight I did it totally wrong. Turns out I should leaned about converting moles into volume of gasses, as that question pertained to chlorine gas.

After the first page, which too a long time, the rest of the quiz wasn't so bad. I answered all but one other question confidently, and that was because I was totally clueless of the chemical formula of the substance mentioned in the question.

Had a lab on hydrates yesterday, and it was pretty interesting. If you want to know more about them look here. The lab was fun because I got to use a Bunsen burner for the first time, and that weird looking contraption used for starting the flame is pretty cool too. Basically we just heated the water out of a hydrate then figured out how water was in the chemical formula.

Moles and Measurement

Back to moles, the mathematical kind. Now I kinda understand how their used and what for. One mole stands for 6.02 × 10^23 representative particles. Essentially representative particles is the estimated number of particles in an sample.

Moles are used for converting the mass of an sample into the number of atoms it contains and vise versa. It kinda works like a middle man between measurements. To do these conversions, you also need to know atomic mass, which is found on the periodic table. A mole map is helpful in these conversions.

The number that is associated with moles is named after Amedeo Avogadro, who did not discover the number, but it is in tribute to him because of the accomplishments related to molecular theory he achieved in his life. More information on him is here.

Still confused? This website should help.

Unit Conversion Project

This unit's project, the second one that is, is converting measurements of food in recipes from standard to metric (SI) units. This project was not really that confusing, and is very relevant to our unit, Matter and Measurements. A useful website I found for turning food measuring units (cups, teaspoons, tablespoons) into grams and liter.

For some of the recipes that I used one of my mothers cookbooks, Better Homes and Gardens. I found the website here.

Dimensional Analysis

Dimensional analysis is basically converting measurements into different units.While I have learned this before in some of my other classes, Mrs. Frankenburg taught it in such a way that it made more sense then some of my other teachers. Sadly I have to remember a lot of the conversions, so that could trip me up on the test on Thursday. I found a website that has most, if not all of the conversion on it.

We also learned about Kelvin today, the temperature that it. Kelvin measures the kinetic energy of particles in a sample. Kelvin was created the Kelvin scale with number of absolute zero (no heat in sample) being equal to zero. Creating a new scale wasn't the only thing that he achieved as seen here.

Moles and Chemisty

A mole is equal to 6.0221415×10^23, that is, in the SI unit of measurement. Chances are you know of moles as little mammals  that dig underground, and like in my house, wage war on the front lawn, looking something like this.

Due to a national mole day (yes it's a real thing, there is even a National Mole Day Foundation), my classmates and I made a stuffed animal mole, and Mrs. Frankenburg loved them. While I don't see any real connection to stuffed animals and chemistry, I did get a day off of lecture so I'm not complaining.