Caroline's weblog

Acid-base studies

You wake up in the morning and you enjoy a nice glass of orange juice.  (Orange juice contains citric acid and absorbic acid.)  Then you go and wash your hands with soap and water.  (Most soaps contain bases.)  While you are getting ready in the morning - your stomach is digesting your breakfast.  (Your stomach contains hydrochloric acid.) 

Almost everything we do in this life is controlled by chemistry.  One big part of chemistry is acids and bases.  Everyone has some experience with acids and bases, such as orange juice, vinegar, baking soda, and bleach.  We will be looking at these acids and bases today in class and determining their pH.  Here is a website that lists some common properties of acids and bases, and also the pH scale. 


The pH scale is an easy way to measure the amount of H3O+ in solution.  A pH of 7 = 1.0e-7M of H3O+ in solution.  (A very small amount!)  This is the pH of pure water at 298K. 

Acids when they react with bases form conjugate bases, and the bases they react with form conjugate acids.  Here is an animation that make this clearer for you.

Water is a very interesting compound that can act as either an acid or a base.  Most acids and bases (except the strong ones) will form an equilibrium when they react with water.  Therefore they have equilibrium constants associated with them.  Ka values describe acids dissolving in water, Kb values describe bases dissolving in water, and Kw values describe water reacting with itself.

Posted at 08:40AM Aug 07, 2006 by CHRISTIAN, CAROLINE in General  |  Comments[4]

Jobs in Sports Chemistry

With a degree in chemistry or in any kind of science field, you can get numerous jobs.  One of the jobs you may be interested in is in sports chemistry.  These kinds of jobs are varied in what you would be working with.  You could be working with althetes, to help them improve their performance, or you could be working on making materials to improve sports equipment. 

Maybe you are interested in getting a job at Gatorade, this is a company that works closely with althetes to develop new ways to hydrate them.  Here is a cooler website than the one above - that includes people who work in performance labs.  The Gatorade labs are located in Barrington, Illinois.

Here is a website that is more about getting a degree in sports medicine and getting a job after that. 

Here is some information about working for Sports Technology International.  They are the company that makes the polymers surfaces, that was featured in an earlier post.  They have manufacturing facilities in Pennsylvania, Shanghai, and Australia.

If you are interested in working closer to home, here is a website from BASF, and they are located in Research Triangle Park.

This is my last sports and chemistry post of the summer session.  I am going to miss writing them for you.  I have learned a lot from writing them, and also from your questions.  I hope that whatever you do with your lives, you will be happy, safe, and healthy.  Keep your eye out for one more post on Monday's lab! 

Posted at 09:57AM Aug 04, 2006 by CHRISTIAN, CAROLINE in Chemistry and sports  |  Comments[7]

Redox reactions

You start your car in the morning and you drive to school (or you get driven to school).  Did you know that your car uses a device to start up, and it is something that we will be studying this week in lab.  Do you know what it is? 

You guessed it - it is a battery!  Actually a car battery is really unique - when you start your car the chemicals in the battery are used in a redox reaction to generate electricity, but when your motor is idling - the electricity in your car goes to recharge the chemicals in the battery! Here is a "How Stuff Works" website about batteries.  It actually gives some ideas of how you can make your own batteries.

Redox reactions involve the transfer of electrons from one chemical substance to another.  This kind of reaction is called an electrochemical reaction.  This is because it involves electrons (electro) and chemicals in one reaction!  The hardest part of electrochemical reactions is remembering which is part of the reaction is oxidizing, and which part of the reaction is reducing.  Here is a pdf that might make this a little bit easier for you to remember. 

In part A of this experiment - you will be determining an order of reactivity.  This can be done easily by testing which chemical substances react with others, and then knowing how to place them in a proper order.  For this part of the lab - if a substance shows a reaction with a certain chemical - this means that it is "more active" than another substance that does not react with the same chemical.

Here is a good website that shows you something like what you will be doing, and you can determine your own order of reactivity before you get into lab.  Press Start on the first page, and then you can either do Activity 1, 2 or 4.  (You can also look at molecular level pictures - so you can visualize what is going on in these reactions.)

In part B of this experiment - you will be determing the electrochemical potential of some redox reactions.  Electrochemical potentials are what determines how much voltage you can get out of a chemical reaction.  Electrochemical potentials are also related to Gibbs Free Energy - and therefore are related to spontaneity of a reaction!

Posted at 04:55PM Aug 01, 2006 by CHRISTIAN, CAROLINE in General  |  Comments[6]