3. Wednesday, May 21 st : “A” Day Thursday, May 22 nd : “B” Day (Sr. finals)  Collect Books  Collect Free Homework Pass  Alka Seltzer Rocket Lab!

4. Collect Books  If you need a few minutes to say goodbye to your chemistry textbook of awesomeness, please do so now…..

5. Collect Free Homework Pass  If you haven’t used your free homework pass yet, good for you!  Turn it in for 10 pts extra credit!

6. Lab: “Alka Seltzer Rockets”  There is no lab write-up for this lab!  This lab will not be graded!

7. Lab: “Alka Seltzer Rockets”  When alka seltzer tablets are put into water, carbon dioxide gas is generated.  In a sealed container, the gas causes an increase in pressure, which must be released.

8. Lab: “Alka Seltzer Rockets”  Alka seltzer is mainly sodium bicarbonate and citric acid.  When these two chemicals are mixed in water, the reaction is exothermic and CO 2 gas is generated along with sodium citrate: H 3 C 6 H 5 O 7 + 3 NaHCO 3 3 CO 2 + 3 H 2 O + NaC 6 H 5 O 7 What kind of reaction is this?

9. Lab: “Alka Seltzer Rockets” Purpose/Hypothesis  Purpose: The purpose of this lab is to demonstrate Newton’s 3 rd law of motion: “For every action there is an opposite and equal reaction” and to control variables in order to achieve optimum rocket performance.  Hypothesis: How high do you thing the rocket will fly? Which variables will optimize the performance/why?

10. Lab: “Alka Seltzer Rockets” Materials  Safety glasses  Alka seltzer tablets  Film canisters with snap-on lids  Water (hot/cold)  Temperature Probe  Timer (can use phone)  Meter Stick/tape measure/tape  Any other materials that you may want to try…

11. Lab: “Alka Seltzer Rockets” Procedure Hints  After adding the alka seltzer to the film canister, snap on the lid quickly.  Place the filled canister upside-down on the sidewalk and back away.  WAIT for it….  If nothing happens, wait about 30 seconds before approaching the canister. WHY do you think it didn’t work?

12. Lab: “Alka Seltzer Rockets” Things to think about…  Size of the tablet  Age of tablet  Brand of tablet  Volume of water  Temperature of water  Orientation of canister  Shake canister  What other variables can you think of…

13. Lab: “Alka Seltzer Rockets”  Since this lab may be kind of messy, we’ll be going outside to launch the rockets.  Again, I won’t be collecting anything and nothing will be graded, but you still want to make a data table to record your results…  Try to optimize your variables to get the maximum height!