Reactions That Form Water

This past week in class, we learned about acid/ base reactions. The driving force of these reactions is water, and they always produce a salt and water as products. We also learned about strong and weak acid and bases:

Strong Acids:

-Produe H+

-Protonate completely 

-HCl, HBr, HI

-If oxygens outnumber hydrogens by 2 or more

Strong Bases:

-Contain an OH- anion

-Disassociate completely

-All group 1 and 2 metals and the -OH anion

Weak Acids:

-Don't protonate completely

-Not on the memorized list

-Parent present

Weak Bases:

-Don't disassociate completely

-Not on the memorized list

-Parent present

Here are some websites that I found that tell how to figure out if something is a strong or weak acid or base and some examples: 

-Strong and Weak Acids

-Strong and Weak Bases

Here is a picture of some common acids and bases:

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Solubility Rules Lab

This past Friday, in Chemistry class, we carried out a lab where we had to combine 10 different elements in a well plate and write down which ones reacted to form a precipitate. After we collected this data, we had to figure out the balanced chemical reaction equations and the balanced net ionic reaction equations for these. Before we conducted the lab, for practice, I went through all of the possible reactions and predicted whether or not they were going to produce a precipitate, using the solubility rules. Here is a website that explains how to do this: Predicting using Solubility Rules

Whenever two chemicals reacted to form a precipitate, they formed a unique color, and a lot of them were very surprising and cool! I did not know that two clear liquids could come together to form something so colorful. Overall, this lab was really fun to do, and it was really helpful in getting me to memorize the solubility rules. Here is a picture of some of the chemicals that reacted to form a precipitate:

Chemical Reactions

This past week in class, we started learning about our next unit, Chemical Reactions. You can tell when a chemical change is occurring thanks to sensory clues. These are things such as:
-color change
-a solid forms
-bubbles form
-heat/flame is produced or absorbed
Here is a link to a website that I found that has a list of chemical reactions that occur in our everyday life: 10 Chemical Reactions

In a chemical reaction equation, there will be a small letter(s) after each compound, telling you what state it's in. These are:
-g (gas)
-l (liquid)
-s (solid)
-aq (aqueous)

Here is an example of what one of these equations might look like:

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When you change the coefficient in a compound, it changes the amount of the element in it. When you change the subscript, it changes its composition and identity.

Here is an example of how to write out a balanced chemical equation:

-Methane reacts with gaseous oxygen to form gaseous carbon dioxide and water.
CH4 + 2O2(g) --> CO2(g) + 2H2O

Here is a helpful website that I found that explains this process more in-depth: Writing a Chemical Equation

Formula of a Hydrate Lab

 This Monday, we took a pre-lab quiz in order to participate in the Formula of a Hydrate lab. My partner, Kendall Kellerman, and I both managed to pass it and carry out the lab. To start it off, we put some crystallized hydrate into a test tube and recorded its mass. Next, we turned on the bunsen burner and held the flame up to the tube until almost all of the water in the hydrate had evaporated and it had turned white. Then, we recorded the new mass. While doing this lab, I learned a couple things:

1. Adding water back in to the anhydride is really cool looking, and it produces heat.

2. DO NOT ADD WATER BACK IN TO THE ANHYDRIDE. It becomes too hot to hold, and is almost impossible to get out of the test tube. Kendall and I know this from experience....

Here is the hydrate when we added the water back to it:

After completing the lab, I wanted to learn some more about how this whole process worked, so I found this website: Dehydrating a Hydrate

Weekly Quiz Reflection

Yesterday in class, we took our weekly quiz over the first half of the chemical composition unit. It had things on it referring to things like molar mass, percent composition, and hydrated compounds. Going into the test, I did not feel very confident at all. I had heard from other students that it was difficult, and I felt unprepared. However, our scores are in the grade book now, and I ended up getting a 15/17! Which isn't perfect, but I'll take it. Moving forward, and getting closer to the actual unit test, I now have a better idea of what exactly to focus on when I'm studying, and I know how some of the questions might be worded. The main thing I am going to focus on is learning how to calculate percent composition of compounds, because I didn't really know how to do that on the quiz.

Here is a link I found that I can use to help me learn about and study this topic for the test: Calculating Percent Composition

Here is another link that I found, and this one explains molar mass in a really easy way to understand: The Mole and Molar Mass

Converting Mass, Moles, and Molecules

The other day in class, we learned how to convert between moles in a balanced chemical equation, mass in grams, representative particles (atoms, molecules, formula units, ions), and the volume of gasses at STP. We were given the "Mole Road Map" to help with this, which can be seen below:

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This map gives you the proper equations to use when converting, and when to use each of them. Here are a couple examples of problems that you can use the Mole Road Map on:

- How many grams are in 5.9 moles of Na?

(5.9 moles Na) x (22.99g Na/ 1 mole Na) = 140g

-How many grams are in 2.13 x 10^25 atoms of Platinum?

(2.13 x 10^25 atoms Pt) x (1 mole Pt/ 6.02 x 10^23 atoms Pt) x (195.08g Pt/ 1 mole) = 6.90 x 10^3g Pt

Here is a helpful website that I found that goes more in-depth as to how to convert in problems like the ones above: Mole conversions

Hydrated Compounds

Recently in class, we learned about a new topic: hydrated compounds. They have water molecules as a part of their chemical formula. These contribute to the crystalline structure of the compound, as seen below:

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Here is a website with an easy to understand, yet very detailed description of hydrated compounds: Properties of hydrates

Hydrated compounds are different than anhydrides, which were once hydrated.

Here are some examples of how to name hydrated coumpounds:

-CaSO4 x 2H2O = Calcium sulfate dihydride

-MgSO4 x 7H2O = Magnesium sulfate heptahydride

-FeCl2 x 4H2O = Iron (II) chloride tetrahydride

Here is a helpful website that I found that describes how the nomenclature of hydrated compounds works: Naming hydrates

When you heat a hydrated compound, it gets rid off the water in it, and changes the chemical structure of the substance and its appearance, as seen below:

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