RXN LAB DATA TABLE REQUIREMENTS Rxn letter or

RXN LAB DATA TABLE REQUIREMENTS • • Rxn letter or demo name Balanced equation Observations/Notes Rxn Type This is by far the most important data table in our class so far! Try hard and do a good job recording what things looked like before and after the changes, what happened during the changes, which materials were used, etc. It may be difficult to come up with the balanced chemical equations & rxn type, but try! We will do a parking lot on them all eventually, but work with your group to figure them out as best you can before that time.

RXN A & B: Procedure, Cleanup & Hints • Rxn A = Everyone needs to light the Bunsen burner today. • Rxn B = Heat a piece of copper wire in the flame. • Be sure to use tongs 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. RXN A & B: Thoughts & Questions • Why is the methane gas included in the equation for rxn A, but not for rxn B? • What explains the color change in reaction B?

RXN C, D, E & F: Procedure, Cleanup & Hints • DON’T FILL UP THE WELL PLATE ALL THE WAY!! (less than half, more like ¼ full is sufficient) • NO METAL ALLOWED INTO THE SINKS!! (use forceps to put unreacted metal in properly labeled waste containers) • RXN C = Cu • Add a small piece of one metal into one well of the LARGE well plate. Add several drops of 3 M hydrochloric acid. Caution: 3 M hydrochloric acid is caustic and corrosive. Wash hands immediately without soap if touched. Repeat for other two metals in new LARGE wells, being sure to add the exact same number of drops of HCl as for the earlier trial(s). • When finished with RXNS C, D & E, use forceps (tweezers) to place any remaining unreacted Cu, Zn & Mg in the proper designated waste beaker. Save liquid in LARGE well plates for Rxn F. • For RXN F, add one drop of phenolthalein indicator to each large well used in RXNS C, D & E. Next, count how many drops of sodium hydroxide solution must be added to turn each of the solutions in the large wells pink. Be sure to GENTLY move the well plate around after each drop of Na. OH is added to ensure it is mixed so that it’s certain the pink color isn’t temporary, but permanent. • Carefully dump the liquid in the well plates into the sink. Use the tap water to rinse the well plate a couple of times before leaving the station nice and clean for the next group. RXN D = Zn RXN = Mg (Be sure to judge which one reacts most vigorously) RXN C, D, E & F : Thoughts & Questions • What strategies could be used to identify the gas bubbles? • Why did some metals react and others didn’t? • Did RXN F require different amounts of Na. OH to turn each well pink? Why/why not?

RXN E – Part 2: Procedure, 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 well is too full, acid can splatter up into and around the sides, making it difficult to complete the flaming splint test successfully (1/4 or 1/3 full is sufficient) • If the test tube is too far above the well plate, not enough gas will be trapped in the test tube (The test tube should be inverted using the test tube holder so it’s touching the well, trapping gas) • While one person holds the test tube directly over the reacting acid and metal in the well plate, the other should be ready to light a match. After the reaction has slowed significantly and enough time has passed to collect quite a bit of gas in the inverted test tube, bring the lit match close to the test tube. Move the flaming splint (lit match) underneath the test tube full of gas IMMEDIATELY as it is lifted off the well. • The result will either happen or not happen immediately. DO NOT HOLD THE LIT MATCH UNDER THE TEST TUBE FOR ANY LONGER THAN A SECOND OR TWO. All splint 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. 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 E – Part 2: Thoughts & Questions • Why did the flaming splint test pop (or not)? • What possible splint tests could be designed for CO 2 or O 2?

RXN F 2 - Cleanup & Hints • Use the small test tube with no label. Dump out any remaining liquid before beginning, but do not rinse with tap water. • Fill the tube a bit more than halfway full with silver nitrate. Place one of the thin copper wires into the test tube with one end submerged and the other sticking out of the top of the tube. • Observe the wire for a minute, then place back into test tube rack. After Rxns G & H are complete, look at this test tube again. • When finished, bring the test tube to the fume hood. Dispose of Cu filament and contents of test tube into properly labeled waste container. Observe, but DO NOT TOUCH the test tube in the hood near the waste container that says, “DO NOT TOUCH!” • Rinse test tube three times with distilled water. • Return clean test tube to test tube rack for next group. RXN F 2 – Thoughts & Questions • What is the crystalline silver material growing on the Cu? • Explain any color change in the aqueous solution. • Why/How does the “DO NOT TOUCH!” example look different than yours?

RXN G: Cleanup & Hints • Potassium iodide catalyzes the reaction, but does not actually take part in the reaction. • Use the larger test tube with the blue label. Fill it with approximately 3 cm of H 2 O 2 and 1 cm of potassium iodide. • Make sure the reaction is really bubbling before you perform the test. It may take as long as 2 -4 minutes. • 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 OR SOLID REACTANTS…remember, you’re testing the gas above the rxn. The glowing splint is carefully inserted to the test tube but DON’T LET THE GLOWING SPLINT TOUCH ANYTHING! • 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 G: Thoughts & Questions • Why did the glowing splint test reignite (or at least not go out immediately)? • Why did the solution change color when the catalyst was added?

RXN H: Procedure, Cleanup & Hints • • Fill the larger test tube with enough copper (II) carbonate so that it is approximately 1 cm deep. BE NEAT! 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. Carefully use the test tube holder to hold the bottom of the test tube in the Bunsen burner flame. Observe and while the rxn is occurring, insert a glowing splint into the tube. 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 LIQUID OR SOLID REACTANTS…remember, you’re testing the gas above the rxn. The glowing splint is carefully inserted to the test tube but DON’T LET THE GLOWING SPLINT TOUCH ANYTHING! All splint waste belongs in the splint waste beaker, unless you are trying to use the same splint later today in a different reaction. Be very careful disposing of the product of this reaction, it’s messy and the test tube may still be very hot. Dump it into the proper waste container but do not wash it out. Place it into the wooden trst tube rack near the waste container. Wipe up the lab table when finished. RXN H: 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?