1. Buffer Solutions Cindy Jiang Next Slide

2. What is a buffer solution? A buffer solution is … Next Slide

3. A solution that can resist changes in pH when small quantities of an acid or a base as well as water are added to it. Next Slide

4. How are Buffer Solutions Made? Two types –Mixture of weak acid and salt –Mixture of weak base and salt The most common buffer solutions include the pH of 4, 7, and 10. Next Slide

5. How do Buffer Solutions Work? Next Slide

6. Adding Hydrogen Adding hydrogen ions (H+) found in acids –Neutralized by the base in buffer solution Results in little to no change in pH Next Slide

7. Adding Hydroxide Adding hydroxide ions (OH-) found in bases –Neutralized by the acid in buffer solutions Results in little to no change in pH Next Slide

8. Uses NOT used to neutralize solutions at pH of 7 Used to minimize change in pH when acid or base is added by stabilizing it Used in a lab to calibrate tools such as pH meters when a certain pH level is needed to be maintained. Next Slide

9. Natural Buffer Solutions Blood –Maintains pH of 7.3 - 7.5 despite the variety of pH in foods –Large changes in pH can lead to major problems in body functions Buffers in water and soil –pH can be drastically changed by pollution –Without buffers, plants and animals can die Next Slide

10. Quiz A common acidic buffer solution is the mixture of ethanoic acid and sodium ethanoate. If a base with hydroxide ions (OH-) are added, what will happen to the pH level? –DecreaseDecrease –Remain the sameRemain the same –IncreaseIncrease

11. A common alkaline (base) buffer solution is the mixture of ammonia and ammonium chloride. If an acid with hydrogen ions are added to the solution, what part of the buffer solution will be used to stabilize the solution’s pH. –The saltThe salt –The acidThe acid –The baseThe base

12. A person decides to eat a lot of food containing bases and acids such as fruits, vegetables, and grains. Will the person be harmed by this large amount of bases and acids? –YesYes –NoNo –Maybe and perhaps I don’t knowMaybe and perhaps I don’t know

13. In a similar way to the textile industry, buffers are used during printing to ensure the ink maintains its normal properties. Incorrect _______ may affect how the ink penetrates and dries on the paper, altering the final result. - pHpH - densitydensity - none of the abovenone of the above

14. Many different therapeutic drugs are synthesized under restricted pH conditions to ensure the stability and clinical effectiveness of these treatments. This is usually achieved with buffer solutions. In addition, buffers can be used to: –Increase the drug’s shelf-lifeIncrease the drug’s shelf-life –Maintain the drug in a near-neutral pH, this way avoiding any irritation to the body tissuesMaintain the drug in a near-neutral pH, this way avoiding any irritation to the body tissues –Both answers above are correctBoth answers above are correct

15. Congratulations! You Got It Right. Next question

16. Congratulations! You Got It Right. Next question

17. Congratulations! You Got It Right. Next question

18. That Is A Good Guess! Too Bad It’s Wrong. Back to the question

19. That Is A Good Guess! Too Bad It’s Wrong. Back to the question

20. That Is A Good Guess! Too Bad It’s Wrong. Back to the question

21. That Is A Good Guess! Too Bad It’s Wrong. Back to the question

22. “A” For Effort. Try Again. Back to the question

23. “A” For Effort. Try Again. Back to the question

24. “A” For Effort. Try Again. Back to the question

25. “A” For Effort. Try Again. Back to the question

26. You Have the Right Idea… Back to the question

27. Congratulations! You Have Successfully Completed This Lesson. Next Slide

28. “Buffer solutions are all around you, just know where to look.” Next Slide

29. Work Cited http://chemistry.about.com/od/acidsbase1/ a/buffers.htm http://www.austincc.edu/biocr/1406/labm/e x3/prelab_3_5.htm http://www.thechemicalblog.co.uk/buffers- in-our-daily-life/ http://www.wyzant.com/resources/lessons/ science/chemistry/buffer-solutions