Solubility Rules Lab

For this lab, we placed 5 drops of one chemical in each spot of a well place then added 5 drops of another chemical to see if they would go through a chemical reaction. We could tell if they reacted because they would form a solid, and in some cases, they would change color. Below is pictures of what the reactions look like when they form a solid.

And here are some chemicals that we used:

Lastly, here's some links with more information:

http://youtu.be/UVVgFEWxF24

http://youtu.be/KVZ_KS45rVg

RedOx Reactions

Key points of RedOX(oxidation) reactions:

1. They are all single replacement.

2. The metals always switch places.

3. The reactions are based off of the reactivity series.

4. The driving force is the transfer of electrons.

5. The element that loses electrons is oxidized and also known as the reducing agent.

6. The element that gains electrons is reduced and also known as the oxidizing agent.

Here are some of my notes from class on oxidation:

And here are some examples:

Here are some videos to help!

http://youtu.be/lQ6FBA1HM3s

http://youtu.be/RX6rh-eeflM

Double Replacement Reactions

Double Replacement Reactions are when two compounds react to form two new compounds. Represented with letters, they look like this...

Two things to remember are:

1. The metals are always the elements that switch places.

2. One element resulting from this reaction will always be solid, assuming that the reaction occurs.

Don't forget the solubility rules linked here to determine which compound product will be soluable...

http://www.chem.sc.edu/faculty/morgan/resources/solubility/

http://youtu.be/7hVKb4ROjZw

Lab Fails: Part 2

Yesterday in class, we participated in the formula or a chloride lab. However, this so the second lab this week that has gone horribly bad for me. We were suppose to heat zinc and HCl to evaporate the water in order to determine the formula for zinc chloride. We didn't get this far though because as we were heating our mixture, it began to foam which we later found out was due to the foul before us rinsing out the beaker improperly, so there was still soap in it. We had to restart, and the same thing happened again, so we restarted for a 3rd time but after the first 2 failed attempts, we didn't have time to finish. Fortunately, Ms. Frenkenberg was kind enough to give us some data to use. Below are some pictures of the lab and calculations with the days we were given.

And here's some links of what is supposed to happen:

http://swc2.hccs.edu/pahlavan/intro_labs/Exp_12_Empirical_Formula.pdf

https://m.youtube.com/watch?v=M2BqSLBDf00

https://m.youtube.com/watch?v=EJf0cwJ_QOw

Hydrate Lab

Yesterday I was able to do my first real lab in chemistry because my partner and I passed the pre-lab quiz. For this lab, we removed the water from the the hydrate Copper Sulfate x nH20. To do this, we first determined the mass of the test tube we would be using. Then we added a thumb-width amount of the hydrate to the test tube and took the mass again with the same scale. Then we heated it with a Bunsen burner 2 times, taking the mass once again after each heating. The hydrate was supposed to go from it's blue color to a white ash color. However, we discovered that we didn't hear it gently enough at first, so we ended up burning the hydrate and it turned brown on the outside while remaining rather blue within. Although we did mess up our results by burning the hydrate, we ended up with about a 28% error for n, as it was supposed to be 5 and we got about 3.8, which isn't too shabby for cooking our crystals way past well done. Below are some pictures of the lab as well as our data.

Moles with Compounds

AlsTo find the molar mass of compounds, follow these steps:

1. Determine the mass of each element in the compound.

2. Determine the number of each atom in the compound.

3. Multiply the number of each atom by its mass and add all of the products together.

4. This sum is going to be your answer and it should be in grams per mole(or g/mol).

Below are some examples from our notes...

Also here is a video to help explain in more detail

http://m.youtube.com/watch?v=zJDhsbjAEtI

Converting to Moles

Moles are the measuring unit that we will be using throughout the year, so it is important that we understand how to convert into moles. With single elements, there are 4 easy steps to follow:

1. Decide what is being asked(starting unit and ending unit)

2. Write down all the given information

3. Use the starting unit to follow to mole roadmap(pictured below) to convert into the ending unit

4. Round to the correct number of significant figures. This will be the least amount of sig figs in any of the present values in the conversions.

Also here are some websites to help with conversions:

http://www.chemteam.info/Mole/Grams-to-Moles.html

http://chemistry.about.com/od/workedchemistryproblems/a/molegramconvert.htm