Buffer SolutionsCindy Jiang

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What is a buffer solution?

A buffer solution is …

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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.

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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.

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How do Buffer Solutions Work?

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Adding Hydrogen

• Adding hydrogen ions (H+) found in acids– Neutralized by the base in buffer

solution• Results in little to no change in

pH

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Adding Hydroxide

• Adding hydroxide ions (OH-) found in bases– Neutralized by the acid in buffer

solutions• Results in little to no change in

pH

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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.

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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

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?

– Decrease– Remain the same– Increase

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 salt– The acid– The base

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?

– Yes– No– Maybe and perhaps I don’t know

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.

- pH

- density

- none of the above

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-life– Maintain the drug in a near-neutral pH, this w

ay avoiding any irritation to the body tissues

– Both answers above are correct

Congratulations! You Got It Right.

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Congratulations! You Got It Right.

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That Is A Good Guess! Too Bad It’s Wrong.

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That Is A Good Guess! Too Bad It’s Wrong.

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That Is A Good Guess! Too Bad It’s Wrong.

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That Is A Good Guess! Too Bad It’s Wrong.

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“A” For Effort. Try Again.

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“A” For Effort. Try Again.

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“A” For Effort. Try Again.

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“A” For Effort. Try Again.

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You Have the Right Idea…

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Congratulations! You Have Successfully

Completed This Lesson.

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“Buffer solutions are all around you, just

know where to look.”Next Slide

Work Cited

• http://chemistry.about.com/od/acidsbase1/a/buffers.htm

• http://www.austincc.edu/biocr/1406/labm/ex3/prelab_3_5.htm

• http://www.thechemicalblog.co.uk/buffers-in-our-daily-life/

• http://www.wyzant.com/resources/lessons/science/chemistry/buffer-solutions