Chemistry Forums for Students > Chemistry Olympiad and other competitions

Chemical Identification for Competition

(1/3) > >>

sammysue07:
I posted this question ealier today, but i cant seem to find it and add to it....

here is my problem, it is for a Science Olympiad competition this coming saturday, and i just got information for this competition today.

we will have ten solids: sodium bicarbonate, sodium sulfite, magnesium hydroxide, calcium carbonate, sodium dihydrogen phosphate, ammonium chloride, zinc chloride, potassium iodide, potassium hydroxide, and aluminum nitrate.

we will be able to choose one of the four chemical solutions to use in identifying the substances: 3M HCl, 3M NaOH, Phenolphthalein indicator solution, or 0.1M AgNO3.

my question i guess is what solution would be the best in determining what the substances are? and should we look at any other characteristics besides what happens with the solution in determining what it is??

i have looked all over the internet, and i am finding really nothing.  i havent had a chance to look at any books, but my teacher/coach does have many different chemistry books....

what do you suggest?

Thanks for all of your help.
samantha

Donaldson Tan:
the line of thought (in my opinion) is which test chemical can identify one of the unknown solutions in one test, then i can use both chemicals (the one i just identified and the test reagent) to identify the rest of the unknown solutions.

sammysue07:
wow.. i am really confused.  i get that you can test with one reagent to find out substance 1, and then use that to find out the other, but which one would you suggest.

we also will have access to distilled or deionized water... with that information, can youi give me any more help??

thank you very much
samantha

savoy7:
Sammysue07,

there are a couple of ways one would go about doing this.  Geodome is right on with his reasoning.  Since this is for a science olympiad contest and you haven't posted any work I will say this:

1)you have access to dH2O

2)maybe this attachment might get you thinking

Post your thoughts and maybe someone will reply with some more help,
savoy 7

savoy7:
I'll try to attach the file again

Navigation

[0] Message Index

[#] Next page