RXN A – Thoughts & Questions RXN A - Cleanup & Hints DO NOT TOUCH the test tube that says, “DO NOT TOUCH!” Estimate the volume of AgNO3, fill the tube approximately halfway full. Instead of a copper coil, place one of the thin copper filaments from the beaker labeled “Cu” into the test tube with one end submerged and the other sticking out of the top of the tube. Wait several minutes to see the rxn begin. When it’s almost time to rotate, carefully bring your test tube to the fume hood. Dispose of Cu filament in trash and pour contents of test tube into properly labeled waste container. Rinse test tube three times with distilled water using wash bottle in the hood. Return clean test tube to test tube rack for next group. RXN A – Thoughts & Questions What is the crystalline silver material growing on the Cu? Explain any color change in the aquesous solution. Why/How does the “DO NOT TOUCH!” example look different than yours?

RXN B-E: Cleanup & Hints (Rxn B) Rinse watch glass in sink and replace in the area on tray designated for Rxn B (Rxn C) Proceed with caution! 1 small swirl in a small drop of HCl is more than enough for this one!!! Replace FeS cylinder in dish with test tube holder and rinse watch glass in sink. Replace watch glass in the area on tray designated for Rxn C. (Rxn D) Rinse watch glass in sink and replace in the area on tray designated for Rxn D (Rxn E) Rinse watch glass in sink and replace in the area on tray designated for Rxn E RXN B-E: Thoughts & Questions What is that terrible smell?!? Any idea why the silver nitrate bottle is all taped up? Why did some combinations of aqueous solutions form precipitates and some didn’t?

RXN F-I: Cleanup & Hints When all three metal and acid rxns have finished, choose the well plate with the least liquid to use for Rxn I (Rxn I) If too much acid has been added to the metal sample, it may not be possible to completely neutralize it without overflowing the well plate…DO NOT OVERFLOW THE WELL PLATE!! When finished with Rxn I, use forceps (tweezers) to place the remaining Cu, Zn & Mg in the proper designated waste tray. Then carefully dump the liquid in the well plate into the beaker labeled “Acid Waste.” Use the tap water wash bottles to rinse the well plate a couple of times before leaving the station nice and clean for the next group. RXN F-I: Thoughts & Questions What strategies could be used to identify the gas bubbles? Why did some metals react and others didn’t? How come the colors of the universal indicator match the colors of pH paper?

RXN J: Thoughts & Questions RXN J: Cleanup & Hints The goal of this rxn is to trap the bubbles formed when Mg reacts with HCl so that they can be identified using a flaming splint test. If the test tube is down too far in the well plate, acid can splatter up around the sides  If the test tube is too far above the well plate, not enough gas will be trapped in the test tube While one person holds the test tube directly over the reacting acid and metal in the well plate, the other should light a flaming wooden splint. ALL splint and match waste should be disposed of safely in splint waste beaker. After the test is over, use tweezers to dispose of the Mg in the properly designated waste tray and dump the liquid in the well plate into the “Acid Waste” beaker . Use the tap water wash bottle to rinse out the well plate a couple of times before leaving the station nice and clean for the next group. RXN J: Thoughts & Questions Why did the flaming splint test pop (or not)? What possible splint tests could be designed for CO2 or O2?

RXN K & L: Cleanup & Hints Everyone needs to light the Bunsen burner today. Be sure to hold the Cu in the outer cone of the burner, not the inner cone. The inner cone is too hot and might actually melt the Cu which can damage the burner if copper drips down into it! Remember that items which have just been held in a fire are HOT! Be careful. Place all waste in the Cu waste beaker and wipe up the table before you move on to the next station if necessary.P RXN K & L: Thoughts & Questions Why is the methane gas included in the equation for rxn K, but not for rxn L? What explains the color change in reaction L?

RXN M: Thoughts & Questions RXN M: Cleanup & Hints Use approximately 1 cm of copper (II) carbonate. NEVER point a test tube that’s being heated at someone. Imagine if the hot solid were to shoot out of the top. Hold it at an angle, away towards a place free of other people. GLOWING SPLINTS SHOULD NEVER TOUCH A SOLID OR A LIQUID! KEEP IT AWAY FROM THE SIDES OF THE TEST TUBE AND DON’T PUSH IT IN SO FAR THAT IT TOUCHES THE LIQUID AND SOLID REACTANTS…remember, you’re testing the gas above the rxn. Be very careful disposing of the product of this reaction, it’s messy. Wipe up the lab table before moving on to the next station. If the test tube is so dirty that you don’t think the next group will get a good result, go exchange it for a new one at the table in the corner of the room. All splint waste belongs in the splint waste beaker, unless you are trying to use the same splint later today in a different reaction. RXN M: Thoughts & Questions Why did the glowing splint test go out? Why do you think the product not being tested by the glowing splint test was black?

RXN N: Thoughts & Questions RXN N: Cleanup & Hints Sodium iodide catalyses the reaction, but does not actually take part in the reaction. Use approximately 3 cm of H2O2 and 1 cm of sodium iodide. Make sure the reaction is really bubbling before you perform the test. It may need longer than 20 seconds, perhaps as much as 1 minute. Feel free to attempt repeat the glowing splint test, but results will probably not be as clear as the first attempt. (why?) GLOWING SPLINTS SHOULD NEVER TOUCH A SOLID OR A LIQUID! KEEP IT AWAY FROM THE SIDES OF THE TEST TUBE AND DON’T PUSH IT IN SO FAR THAT IT TOUCHES THE LIQUID AND SOLID REACTANTS…remember, you’re testing the gas above the rxn. All splint waste belongs in the splint waste beaker, unless you are trying to use the same splint later today in a different reaction. RXN N: Thoughts & Questions Why did the glowing splint test reignite (or at least not go out immediately)? Why did the solution turn yellow when the catalyst was added?

RXN O: Thoughts & Questions RXN O: Cleanup & Hints If you try to put the sodium carbonate into a test tube that’s wet, it’s crazy messy and the chances of this experiment succeeding are small. The group before you should have placed a brand new, clean, dry test tube in the rack for you. If they haven’t, go get one now & please do a better job following cleanup instructions that they did  Use approximately 1 cm of sodium carbonate GLOWING SPLINTS SHOULD NEVER TOUCH A SOLID OR A LIQUID! KEEP IT AWAY FROM THE SIDES OF THE TEST TUBE AND DON’T PUSH IT IN SO FAR THAT IT TOUCHES THE LIQUID AND SOLID REACTANTS…remember, you’re testing the gas above the rxn. When finished, rinse the test tube out in the sink, place the wet used test tube in the big beaker of used dirty test tubes on the table in the corner and bring a brand new, clean, dry test tube back for the next group to use. All splint waste belongs in the splint waste beaker, unless you are trying to use the same splint later today in a different reaction. RXN O: Thoughts & Questions Why did the glowing splint test go out? What result would you expect for this style of experiment if the solid was CuCO3?