Formula of a Chloride Lab

Yesterday in class, we did the Formula of a Chloride Lab. To complete the lab, we put a small piece of Zinc in a beaker, then added Hydrochloric acid. Next, we put the beaker on a hot plate, and heated the chemicals. The Zinc dissolved into the Hydrochloric acid, then water began to be driven off. We heated the mixture until there was no liquid left, and there was a salt left in the beaker. Then, we cooled the beaker and took it's mass. The purpose of the lab was to determine the empirical formula formula for the salt at the end of the lab. In our results, we got a ratio of one Zinc to 2.068 Chlorine, which was a 3% error, as the real ratio is one Zinc to 2 chlorine atoms.

https://en.wikipedia.org/wiki/Zinc

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Empirical Formula Help

Formula of a Hydrate Lab

We ran the Formula of a Hydrate Lab on Monday this week, and it was very interesting and connected to our lesson perfectly. We started with Copper (II) Sulfate pentahydride (we didn't figure out that it was pentahydride until completing the lab), and we heated it using a bunsen burner. We heated the chemical in a test tube for about 5-7 minutes, then let the chemical cool before we took it's mass. We took the mass in order to figure out the mass of the water that was driven off, so we could try to find the number of water molecules in the substance. After weighing, we reheated the substance to drive off any additional water, and re-massed to chemical. Then, we calculated the number of water molecules in the substance, and determined that the answer was 5.

http://www.fphoto.com/?stockindexonline.com=1

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How to find the Formula of a Hydrate

Hydrates

Today in class, we learned about hydrates, which are chemical compounds that have water in them. If the hydrate loses its water molecules, then it becomes an anhydride. The nomenclature for hydrates is simple, for all you have to do is add a prefix for the number of water molecules to the root "-hydride" to the end of the anhydrous chemical. We also learned about using hydrates to solve equations. The equations took a lot of work, but the work was fairly simple and easy to complete. The process is very tedious, though, so a small mistake could lead to a disaster at the end.

http://chemiru.com/products/ammonium-sulfate/

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Hydrates
Hydrate Equations

Chemical Composition Pre Test

The Chemical Composition pre test was extremely hard. I'm not sure that I have ever seen anything on the entire test. The main things I noticed were there were a lot of numbers referring to the masses and percentages of atoms in particular compounds, but I still really had no idea what to do. As I got further and further into the test, I started just guessing, due to the fact that it was extremely hard, as well as it does not factor into my grade. Also, I am excited to learn this new material so that when the post test comes, I'll be able to actually understand what the questions are asking me to do.

http://sublimestudies.com/welcome/part4-implementation/screen-shot-2012-08-12-at-6-20-46-pm/

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Definition of Chemical Composition

Empirical Formula Intro