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Re: Environmental Chem
Posted: April 6th, 2009, 12:34 pm
by emilyy18
ok thanks!!
in the specs it said that we would be using graphing calculators and probes to determine temperature, pH, and nutrient levels in the soil.. but from what I have read, people have been using other methods of soil testing at previous competitions.. should I learn the other methods or just continue studying use of calulator and probes??
Re: Environmental Chem
Posted: April 6th, 2009, 2:53 pm
by dickyjones
Generally, you'll be given the procedures for the labs to perform (or instruments to use). But it still always helps to practice labs beforehand, most of the NPK/pH tests can be found under $30. Even if you can't get your hands on one of those, just get some sort of chemistry lab (it doesn't even have to be about enviro chem) and go through it with your partner so that you guys will know how to work together if you get a new lab that you haven't done before.
At my only competitions in this event, we had a TI calculator with two probes. One was a temperature probe and one was a colorimeter probe. You just attached both and with the temperature probe compared the temperature change in 5 minutes of a dry soil sample and wet soil sample in ice. For the colorimeter probe, a sample of digested soil was given as well as the wavelengths of different metals for best absorbance. So to determine the concentration of a metal ion in the solution, you would place the probe at the proper wavelength for that metal (one of most absorbance) and then put down the absorbance measured by the probe. Then on a given standardized curve you would find this absorbance and match it with the corresponding concentration.
They could give you completely random instrumentation, but a good supervisor will likely give you a brief introduction to the tools. And if they don't, you generally can work it out for yourself if you have a little bit of time.
Re: Environmental Chem
Posted: April 7th, 2009, 10:03 am
by emilyy18
will the lab be that complicated in divison B as well?? I'm only in 8th grade, and even though I've taken Earth Science, I had no idea what you just said there! Well I kind of got it, but my partner is in 6th grade, so this could be complicated for her.
Re: Environmental Chem
Posted: April 7th, 2009, 11:49 am
by dirtisfun
does anyone know any specific things to study

Re: Environmental Chem
Posted: April 7th, 2009, 12:12 pm
by GGuy5
emilyy18 wrote:will the lab be that complicated in divison B as well?? I'm only in 8th grade, and even though I've taken Earth Science, I had no idea what you just said there! Well I kind of got it, but my partner is in 6th grade, so this could be complicated for her.
just ask the event supervisor for help
Re: Environmental Chem
Posted: April 7th, 2009, 12:25 pm
by Avis_de-Incendia
Question:
A) What is ashing?
B) Why would one digest soil with strong acid?
Re: Environmental Chem
Posted: April 7th, 2009, 12:25 pm
by Avis_de-Incendia
Question:
A) What is ashing?
B) Why would one digest soil with strong acid?
Re: Environmental Chem
Posted: April 7th, 2009, 2:28 pm
by emilyy18
thanks!!
ashing- A test to deduce the amount of ash forming material present in a petroleum product so as to decide its use in certain applications. Ash-forming materials are considered to be undesirable impurities or contaminants.
Re: Environmental Chem
Posted: April 7th, 2009, 6:57 pm
by 2win
Oh my gosh, thank you so much [for the answer]! My partner(AsllaPiscu) and I have been looking for that everywhere and we haven't been able to find it. Thank you sooooooo much!
But now, does anybody have anything on "digesting soil with stron acid"?
Re: Environmental Chem
Posted: April 7th, 2009, 7:31 pm
by 2win
dirtisfun wrote:does anyone know any specific things to study

please read the posts before you and also check out the wiki.