1. Answers to Worksheet #6 Equilibrium Practice

2. 1.Reversible Reaction: A reaction that will not go to completion. Can break down products back into reactants. 2.Chemical Equilibrium: Rate of forward reaction = rate of reverse 3.Le Chatelier’s Principle: If the reaction or “system” in equilibrium is stressed, the reaction will work to reduce the stress and re-establish equilibrium.

3. 4. Describe a process in everyday life that is an example of equilibrium (or that shows two competing processes) Consider a bathtub that is filled to a certain level, then the plug is removed while water is added from the tap so that the input of water = the outflow. The amount of water in the tub will remain at a constant level while there is a constant flow of water through the bathtub "system."

4. 5. How do you show that a chemical reaction is reversible? With a 6. How do you show that a chemical reaction is in equilibrium? With a 7. What are some of the ways that you can stress a chemical system? Add/remove reactants/products, change pressure or change temperature

5. 8. According to Le Chatelier, how will a system respond to stress? reaction will work to reduce the stress and re- establish equilibrium.

6. O 2 + 2H 2  CH 3 OH + heat 9. Add O 2 favors forward makes more product 10. I take away H 2. favors reverse makes more reactant 11. I take away CH 3 OH. favors forward makes more product The arrow shows what the reaction will do to try to regain equilibrium

7. O 2 + 2H 2  CH 3 OH + heat 12. Is the reaction endothermic or exothermic? Exo 13. If I increase the temperature of the reaction what will the system do? Will start to make more reactants

8. 14.For any reaction, what would the effect on the forward reaction rate would the following changes have? a. Adding a catalyst – increases it b. Increasing reactant concentration – increases it c. Decreasing reactant concentration – decreases it d. Increasing product concentration - decreases it e. Decreasing product concentration – increases it f. Heating the system – depends (for endothermic – it would increase it, but for exothermic it would decrease it)

9. 15.A system reaches equilibrium when: d. the forward rate = reverse rate 16. The owner of a chemical company makes liquid sulfur by using the following reaction: 2H 2 S + 3S0 2  3S + H 2 O As the owner of the chemical company, you want to make as much sulfur as possible. What are two ways that you can do that? Explain why they will work. Remove product, shifts reaction forward or Add reactant, shifts reaction forward

10. N 2 (g) + 3H 2 (g)  2NH 3 (g) + 22.0 kcal heat Stress Draw Teeter- totter when stress applied Equilibrum shifts N 2 concentration H 2 concentration NH 3 concentration 17. Add N 2 Right decreasesDecreasesincreases 18. Add H 2 19. Add NH 3 20. Remove N 2 21. Remove H 2 Right decrease X increases Leftincreases X Left X increase decreases Left increase X decreases

11. N 2 (g) + 3H 2 (g)  2NH 3 (g) + 22.0 kcal heat Stress Draw Teeter- totter when stress applied Equilibrum shifts N 2 concentration H 2 concentration NH 3 concentration 22. Increases Temp left increaseincreasesdecreases 23. Decreases Temp 24. Increase Pressure 25. Decrease pressure rightdecrease increases right decrease increases Left increase decreases 1 mole + 3 moles2 moles 4 moles vs2 moles