Friday, December 7, 2012

Three Questions


Recently I have finished the test, the latest homework, and lots of labs! In so doing, I have learned about the mathematics involved in the labs, and solving problems related to solubility, redox reactions, and volumetric analysis. Next I  plan to put the finishing touches on my labs for Monday, and finish the glog on my book! 

Monday, December 3, 2012

Titration... in real life


So just for a second pretend you are Robert Angus Smith. Its 1852 and you are studying air pollution in an age marked by the growth of industry.

You live in Scotland, which just happens to be the place famous for having the most acid rain ever.  That would be a subject of scientific interest, I mean, its only sulfuric acid pouring from the sky, right? But you jump right in and begin your investigation. I mean, who wouldn't want to know why 109.16 grams of sulfuric anhydride would ever be in the position to contaminate every single gallon of rainwater. 

After all of your pioneering research you publish a book called air and rain, in which you formally begin your own field of research, chemical climatology.
 Then you go down in history as the father of acid rain, which does sound pretty bad when you think about it, I mean, acid rain has pretty volatile effects on ecosystems, but we won’t get into that, the poor guy only coined the term, after all.
Now pretend you are a modern day chemical climatologist, and you study the ideas brought about by guys like our friend Robert. Being a chemical climatologist, you  say you want to study the acidity and composition of the rainwater, contaminated or otherwise in the immediate area. Now you are studying how precipitaion responds to an increase in output of air pollutants by industry, or something similar. After using ion exchange chromatography to analyze your samples for various ions, you then set out to identify the degree of contamination. Immediately, you think of everything you learned about titration and how it can give you information on the proportions of chemicals in solution. After identifying sulfuric acid in the solution, you titrate it to neutrality with sodium hydroxide. By finding out how much sodium hydroxide is necessary, you can figure the degree to which the rainwater is contaminated. 
                                               
Picture from http://amcheminfo.blogspot.com/
From this, it is absolutely clear that titration is essential in the environmental sciences. For the same purpose, it is also used in waste water analysis, though a bit more elaborately, for the same purpose. Figuring the extent of contamination. In this case to meet standards. 

As a method of chemical analysis, titration has a clear and straightforward purpose. It tells us about a solution, and as we have seen, that can be absolutely vital. 

Sources
http://www.titrations.info/acid-base-titration-sulfuric-acid
http://www.people.carleton.edu/~bhaileab/environmentalgeology/RainWater.pdf
http://en.wikipedia.org/wiki/Ion_chromatography
http://archive.org/stream/airrainbeginning00smitiala#page/234/mode/2up
http://ca.answers.yahoo.com/question/index?qid=20100308180158AA7Z2Vo
http://cpe.njit.edu/dlnotes/CHE685/Cls06-1.pdf

Friday, November 30, 2012

3 Questions!

 Recently I have completed the raw data for four new labs! In doing so I have learned about activity series, solubility rules, redox reactions, and the reactions of aqueous ionic compounds with metals. This week has been absolutely action packed, I have learned to categorize reactions, predict probable products and balance charges. I also learned about the concept of molarity and its applications in dilutions, stoicheometry, and the upcoming lab I need to prepare for. Next I plan to complete this weeks labs, prep for next weeks labs, finish all flipped questions, homework and take lots of notes on the online lectures. It just keeps getting busier.

Friday, November 23, 2012

Everyday reactions!!!

 Life as we know it is based on chemistry, and it serves a very integral function. We ourselves are the result of the innumerable chemical reactions that serve as the basis for our being. These interactions between matter are essential to the world as we know it and play vital roles in the most commonplace things.

Technology is also important in our increasingly technology dependent society, and it to is powered by reaction. Our cars, cell phones, laptops, toys and flashlights are all powered by battery. Although there are many types, their energy has a chemical origin. Take the common AA battery, the type that never seem to have when I need it, and find randomly when I don't. These alkaline batteries generate power from an oxidation reduction reaction. There are two parts of the battery that I care about, the cathode and the anode.  In the anode, composed in this case by a zinc powder, electrons are produced through oxidation. The cathode (here, MnO2 and other assorted compounds) absorbs these electrons in the reduction part of this. As a result of these reactions, electricity is produced. Until, of course, the limiting reactant is all reacted, and your flashlight suddenly goes out, the batteries "dead".


2 MnO2(s) + 2 NH4Cl(s) + Zn(s)  Mn2O3(s) + H2O(l) + Zn(NH3)2Cl2(s)

Balanced chemical equation of the redox reaction in a battery! Thanks to http://library.thinkquest.org/C004970/redox/cells.htm 


I don't know why these products in particular are yielded, I don't know of any patterns in this reaction type. It is most likely a redox reaction because on one side, there is the polyatomic ion ammonia, and not the other. Also, Zn, (with a zero charge on the left) combines to form the compound on the right implying a now nonzero charge.

I care about this reaction, and other everyday reactions because I depend on them. I can't imagine life without batteries, or dish soap, or a non  patinated statue of liberty. These small reactions make a big difference, and other small reactions sum to make us possible! 

I am excited to learn more about redox reactions during the coming days!
from: http://www.greenphillyblog.com/philly-represent/philly-recycling/where-can-i-recycle-used-batteries/ 
Sources:
 http://electronics.howstuffworks.com/everyday-tech/battery3.htm
http://micro.magnet.fsu.edu/electromag/electricity/batteries/lithium.html
http://suite101.com/article/how-do-batteries-work-a20363

Three Questions

This week I completed the categorizing chemical reactions lab, worked on the EC placement, posted a new blog post, and watched the 4.2 notes!

I have learned to categorize 5 basic equation types! I have also learned about net ionic equations, electrolytes, and non-electrolytes. I have also gotten to review all of our previous topics by doing the EC placements!

Next I plan to finish HW # 10 and finish up the flipped questions.


Friday, November 16, 2012

Three Questions

This week I have completed the test, and have the practical bit of the next lab. Next week I plan to finish the conclusions/results for the lab and turn it in. Through the lab, I have learned about categorization of reactions. Interesting stuff!

Wednesday, November 14, 2012

Baby Bottle Lab

The baby bottle lab was successful! My bottle, propelled by the reaction of vinegar and baking soda, traversed the full distance for a triumphant outcome. The amount of trial and air was minimized by experimental awareness, as well as working within the optimal ratio of vinegar and baking soda to eliminate un-reacted materials. As I saw in my first two trials the distance traveled, I was able to estimate about how much more I needed based on the fraction of how far I had gone, vs how far left to go. Limiting reactants are determined by stoichiometric amounts simply because molecules do not have the same mass, therefore, in order to make use of the molar ratio, one must convert to moles, and do the stoichiometry thing. If the ratio in the reaction is one molecule to another, on gram of that thing to a gram of the other is not the same thing, one could be heavier than the other, so one gram would be less of that thing than the other. If I were to do this lab again, I would be sure to gather more detailed information to try and discover a relationship between CO2 produced and distance traveled, maybe after I could then redo the experiment with a relation to time rather than distance.