Ib Biology Hl 3,4 Lab

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Responses to pH Change|
How do living systems respond to a change in pH?|
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Ravneet Kaur|
HL Biology 3,4|

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Results:
pH Levels of Water with NaOH (±0.2)

Initial| 5 drops| 10 drops| 15 drops| 20 drops| 25 drops| 30 drops| 6.0| 6.4| 7.2| 7.6| 8.5| 9.5| 11.0|

pH Levels of Water with HCl (±0.2)

Initial| 5 drops| 10 drops| 15 drops| 20 drops| 25 drops| 30 drops| 6.4| 5.5| 3.5| 3.0| 2.75| 2.75| 2.5|

pH Levels of Chicken Liver with NaOH (±0.2)

Initial| 5 drops| 10 drops| 15 drops| 20 drops| 25 drops| 30 drops| 6.4| 6.4| 6.6| 6.8| 6.9| 7.0| 7.0|

pH Levels of Chicken Liver with HCl (±0.2)

Initial| 5 drops| 10 drops| 15 drops| 20 drops| 25 drops| 30 drops| 6.2| 6.0| 5.75| 5.5| 5.0| 4.75| 4.75|
pH Levels of Potato Juice with NaOH (±0.2)

Initial| 5 drops | 10 drops| 15 drops| 20 drops| 25 drops| 30 drops| 6.4| 6.5| 6.8| 6.9| 7.0| 7.2| 7.4|
pH Levels of Potato Juice with HCl (±0.2)

Initial | 5 drops| 10 drops| 15 drops| 20 drops| 25 drops| 30 drops| 6.4| 6.0| 5.5| 5.4| 5.1| 5.0| 4.7|

Qualitative Data:
* During trials with water and HCl – changing color as the more drops are being put in * Water and HCl = ending color was near orange
* Less color change with water and NaOH
* Water with base and acid had dramatic pH changes
* The chicken liver gets thicker with further drops of NaOh * The drops of NaOH in the chicken liver separates the liquid where they fall * Chicken liver’s pH had a plateau at 25/30 drops for both HCl and NaOH * Initial pH levels of 3 substances are similar

* Potato juice did not have significant increases or decreases in pH Data Processing:
Equation used: [pH level at 30 drops] – [pH level at 0 drops] = change in pH

Using results from water and NaOH
11.0 (±0.2) – 6.4 (±0.2) = 4.6 (±0.4)
Using results from water and HCl
2.5 (±0.2) – 6.4 (±0.2) =...
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