Weekly Quiz

Yesterday was this unit's weekly quiz. I've felt pretty good about this unit, and that feeling also applied during the quiz. It went by in a breeze, and I had time to double check all of my answers (I basically was able to work out all the questions a second time just to make sure!). It's always a great feeling when a quiz/test doesn't give you a tough time. Also, much of the quiz came directly from the online practice which I always use to study, so that really helped! All in all, I'm feeling great about how I did on the quiz.

Here are some links for future studying: 

http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch6/relativeenergypractice.html

http://www.rsc.org/learn-chemistry/wiki/Quiz:GeneralI001:_Electron_configuration
https://www.youtube.com/watch?v=I58ByiqnXcY

Spectroscopic Analysis Lab

On Tuesday, we performed yet another lab. This lab was not nearly as exciting as the flame test lab. For this lab, we adjusted various knobs on a spectrophotometer and found the amount of light in blue and pink solutions. It was really difficult to adjust the knob so that the number read exactly what it was supposed to. This was extremely time-consuming as we had to re-adjust the knobs for every single different wavelength. Additionally, it was dull as all the lab consisted of was a) adjust the knobs and b) record the number. Not very exciting. But we did get to learn how to make graphs in excel, which isn't as hard as I thought it would be, and I love anything that has to do with computer programs, so that was fun.

Day 1: Lecture

We've started a new unit, and it has been going pretty well. At first, the unit seemed a bit confusing, but it all began to make sense gradually. The first lesson of the unit was on wavelengths of light. We learned the formula for the speed of light (C= frequency x wavelength) and for energy (E= Planck's constant x frequency). These two formulas were easy to understand as problems associated with the lesson are pretty basic plug-and-chug. Yesterday, we learned about the electron configuration of elements. This lesson was chockful of vocab and steps to memorize. It was definitely a bit confusing and time-consuming at first to figure out each element's different electron structure and diagram and to memorize all the little rules for different types of elements. However, I soon began to understand it, and I even think it's a bit fun (Something I have NEVER said about chemistry, so that's saying a lot!). 

http://chemwiki.ucdavis.edu/Core/Inorganic_Chemistry/Electronic_Structure_of_Atoms_and_Molecules/Electronic_Configurations

Some links for review on these lessons:

http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch6/electronconfigpractice.html
http://www.sciencegeek.net/Chemistry/taters/Unit2ElectronNotations.htm
https://www.youtube.com/watch?v=2AFPfg0Como

On the other hand, our acid-base test scores have arrived, and I am incredibly happy about my score. I did a lot better than I expected, and being that that unit was supposedly the hardest unit of the year, I feel really great. Thank the chemistry gods.

Flame Test Lab

Today in class we had another lab, one which may be my favorite lab we've done all year: the Flame Test Lab. Basically, we placed several different chemical compounds and solutions in the flame of a Bunsen burner to see the various colors each one produced. It was really awesome to see the vivid colors that varied among each metal. The smell was really reminiscent of summer (fireworks, bonfire, you get the picture) when we first walked in due to the Bunsen burners. I enjoyed observing the color changes, and I look forward to hopefully doing more labs like this one!

Unit Exam...

I have heard countless stories of how the acid base unit test is THE most difficult test of the year, and I arrived to school last Thursday fearing for my life. Apparently a good chunk of this unit test was basic vocab, essentially textbook comprehension questions, which I'm pretty good at memorizing. I've heard there are maybe one or two math problems that are very hard, but other than that, the rest of the test went by in a breeze. I'm hopeful that this is the case because I would be very disappointed if I got a grade similar to the last exam.

Some links I used to study and will be using for the final:
http://www.chemtutor.com/acid.htm#math
https://www.khanacademy.org/science/chemistry/acid-base-equilibrium/titrations/v/titration-calculation-example

Unknown Acid Lab!

Unknown Acid Lab

Last week, we worked on another titration lab that is pretty much identical to the previous titration lab (Acetic Acid lab). The only thing that's changed is that we're not using acetic acid, rather an unknown acid. We still titrated the unknown acid with NaOH, just like the acetic acid lab. Another thing that's been added to this lab is that we have to heat the solution as the unknown acid does not dissolve as easily as acetic acid. It's pretty neat seeing the solution turn into a mini tornado when the magnetic thingamajig is added to the flask and spins due to the magnet in the heater.
One frustrating thing about this lab is that we can't seem to get a good percent error like last lab where we got less than 1% error! The first trial of this lab gave us a 14% error, which is definitely not preferred, and the second trial gave us a 7% error, however when we re-did the experiment the following day, we were able to get a less than 1% error like the first lab.

Solution being stirred

Nuetralization Reactions?!

 In Ahrrenius acid/base reaction the products are the same - a salt and water

• salt is formed from the cation of a base, and the anion of the acid

• the strengths of the parent acid and parent base are the determiners of the strength of the salt

• strong acid + strong base = neutral salt

• strong acid + weak base = acidic salt

• weak acid + strong base = basic salt

• weak acid + weak base = neutral salt

• the strongest parent runs the reaction

The Hydrogen Ion in Water

•  the hydrogen ion is simply a proton (nucleus of a hydrogen atom without its valence electron)

• is water, clusters of hydrated hydrogen ions form

• the simplest cluster is hydronium (H3O)+

• H+ is the same is H3O+

Water as an Acid and a Base

     Water can act as an acid because it can donate a proton. Water can be a base because it can accept a proton to form the hydronium ion.

1st Titration Lab

Titration Lab

Last week, we worked on a new lab. The purpose of the lab is to standardize a solution of NaOH with KHP, and then, use that solution's molarity to determine the percentage of acetic acid is in vinegar. To start, we filled the buret with NaOH, and measured out some KHP on a weigh boat. We transfered the KHP to a flask, and filled it with water to make a solution of 75 mL. Next, we added three drops of phenolphthalein to act as a color indicator for the endpoint. Lastly, we slowly drained the NaOH solution into the flask until the solution reached a permanent pink color. This was the hard part as we never knew exactly when to stop, but then again, we couldn't go too slowly as we needed to finish within a class period. Although, I thought I sometimes went too overboard with the NaOH, we ended up getting a 4.50% error! All in all, I enjoyed this lab and watching the clear liquid turn into a bright pink in a matter of drops.

KPH

The solution turns pink where the base hits it, but then soon disappears

The endpoint has been reached!

Acid-Base quiz

Acids & Bases Weekly Quiz

The first quiz proved to be quite a relief. All throughout the day before, I had been stressing over this quiz as I had not done so well on the last unit test. Thankfully, when it came down to actually taking it, it was pretty much half as hard as I thought it would be. I had no trouble answering any of the questions, and I had time to double (and for some, triple) check my answers. These are the kinds of quizzes I thank the chemistry gods for blessing upon me. I have a good feeling about this one.


Hopefully, the rest of the unit won't get much harder than what we've learned so far, but I'm probably jinxing myself. 
Here are some of the links I used to study with which may come in handy for the unit test:
https://www.youtube.com/watch?v=Xeuyc55LqiY
https://www.youtube.com/watch?v=l5fk7HPmo5g
http://www.chemteam.info/AcidBase/AcidBase-Problems&Video.html

The Acid-Base Lessons

Lessons on Acid-Base

We started our new unit on acids & bases on Wednesday 2 weeks ago. The majority of the lessons are not very complex nor difficult to understand. I may just need to study some of the vocab again. Wednesday's lecture consisted of identifying the differences between acids and bases, strong vs. weak, and Arrhenius vs Bronsted-Lowry acids. This was probably the most difficult out of the two lectures we've had so far as it was very vocab-packed, and there are some rules that need to be memorized in order to identify what type of acid or base a substance is. Recent lectures were more math based in that we had. It was basic math and involved a simple formula to find the M of either H or OH ions in a reaction. Overall, these two lessons have not been difficult, and I am hoping that the rest of the unit will not be super bad (but it probably will).
A good summary of what we learned:http://www.chem.wisc.edu/deptfiles/genchem/sstutorial/Text12/Tx121/tx121.html