HOW THe HELL • I know what your Thinking. • How the hell do I do this? • If you follow my directions and do your part by writing good notes, I GAURENTEEyou will get one of those stupid buttons… I Solved the Chemistry Ten Test Tube Mystery
Preparation • You are going to need a SHIT LOAD of CLEAN test tubes for this experiment, So borrow them, steal them, whatever just make sure you have at least 30, 10 or 15cm test tubes. • Another Thing.. They are going to tell you which 6 Cations you should expect when you are doing your experiment. So get that list and know what happens which each acid and base when added to them……..
STEP 1Identify the Bases • Okay you are given two of three bases. (NaOH, NH3, Na2CO3) • Test for slipperiness by putting a single drop of each of the 10 unknowns on your finger. If you feel slipperiness and want to make sure, add a drop if water which should make it more slippery. If you find and confirm slipperiness then its either the bases NaOH or Na2CO3 . • Okay now you know its either NaOH or Na2CO3. to figure out which one it is you have to wait till you test all your unknowns with this base because once its hits the acid if it is Na2CO3 it will bubble other wise if its NaOH your going to feel a crazy amount of heat. • To find NH3 you have to smell all ten test tubes for it. You know what ammonia smell like by now so smell for it and you will find your NH3.
STEP 2Add Bases to other 8 Test Tubes • Okay take your bases and add them DROPWISE to each of the other 8 test tubes. Be careful here because some amphoteric ions will precipitate with 1 drop of NaOH and NH3 But will dissolve with excess base. • Look for heat, precipitate, note weather excess base will dissolve it or not, and bubbling.
STEP 3Identify the ACids • In addition to the 6 Cations, and 2 bases, you will be given 2 acids of 3 acids ( HCl, HNO3,H2SO4). • Identify by using the bases. When mixed with your already known bases you will get a lot of heat. • Acids will bubble with Na2CO3
STEP 4Add Acids to other 8 Test Tubes • Okay take your acids and add them DROPWISE to each of the other 8 test tubes. • Look for heat, precipitate, color change etc.
STEP 3Identify Everything Else • Using the solubility rules and the known reactions on the following slides identify the rest of your unknowns. • This shouldn’t be too hard because not everything reacts the same with all acids and bases. If you correctly identified them the rest should be a breeze………
Known Reactions With Acids • ALL acids give off heat when mixed with NaOH and NH3 • ALL acids form bubbles Na2CO3 • HNO3does not precipitate with anything • HCl and HNO3 give off smoke with NH3 • HCl precipitates with Ag+ Hg + and Pb+2 • HCl turns Fe(NO3)2 yellow • H2SO4 precipitates with Ba+2 Pb+2
Known Reactions With Bases • ALLpercipitate with all cations except NH4+ • Excess NaOH will dissolve Pb+2 Sb+3 Sn+4 Al+3 Cr+3 Zn+2 • Excess NH3will dissolve Ag+ Cu+2 Ni+2 Zn+2 • NaOH Creates a blackish brown pecripitate with Ag+ or Hg+ • NaOH or Na2CO3 will give of Ammonia vapors when mixed with NH4+