Friday, November 18, 2011

How much Calcium is there in Total? Day 1


This is what I do in Analytical Chemistry:

We want to determine the amount of calcium in TOTAL cereal. We can do this two ways: by precipitating the calcium out or by a redox reaction (titration). Lucky me I get to do it both ways.


The first day is pretty easy, just making solutions to use for the other two days.

First, the cereal is digested in 6 M HCl. The lovely golden flakes turn in to a horrible, stinky brown goo.


Next, the goo is filtered to remove the organic chunks. Ideally, all of the calcium is washed out into the filtrate flask and then filtrate can be diluted and analyzed.



 Note: Do not rip the filter paper because then in has to be re-filtered, which takes considerably longer than you might expect.



Two other solutions are prepared. 

One is 1L of 1 M sulfuric acid (M means molar, which is just a unit of concentration), which is made by diluting 6 M acid. Over all its a rather boring and tedious process due to the fact that dumping  this particular acid in water releases a lot of heat, so you have to add the acid in small portions and monitor the temperature.  Its redeeming quality is that the stir bar makes a pretty awesome tornado in the beaker :D 


 The other is a solution of 1.6 g KMnO4 (Potassium Permanganate) in water. It is very lovely shade of purple that has to be hidden away in a ugly brown bottle to prevent decomposing as it will react with light if over exposed.


To be continuted... (I know you're on the edge of your seat)
 





3 comments:

  1. So...just how much calcium is in Total.....there seems to be no end to this experiment:)

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    1. Haha.. Yes I'm not much of a blogger and forgot to take pictures of the rest of the experiment. However, we did discover that the box is in fact truthful and actually contains more than the proclaimed daily value of calcium. I have a copy of my lab report if you are interested. ;)

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