Measuring PH Lab - In this lab you measure the PH levels of multiple liquids. This document contains PDF

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In this lab you measure the PH levels of multiple liquids. This document contains an analysis and conclusion as well as the answers to the lab itself, the hypothesis, and the question....

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Measuring PH Lab

Pre-Lab InformationPurpose- Explore acids and bases using 2 different pH indicators. Time- Approximately 45 minutes Question- How can you use a red cabbage solution to determine the pH of a solution? Hypothesis- If you can measure the pH of a range of acids and bases with a universal pH indicator, then you can use those values to calibrate a cabbage pH indicator. Summary- Using pH indicator paper, you will measure the pH of several acids and bases. This data will help you establish a key for a cabbage indicator. Finally, you will rate the pH of three everyday solutions with this new cabbage indicator.

Table A: Control Solutions (in order from most acidic to most basic) Solution Name

0.1 M HCI

0.001 M HCI

0.00001 M HCI

Distilled Water

0.1 M NaOH

0.001 M NaOH

0.00001 M NaOH

pH using – log[H+]

1

3

5

7

9

11

13

Indicator Paper Color

Red

Orange

Yellow

Light Green

Dark Green

Blue

Purple

3-4

5-6

7

8-9

10-11

12-13

Indicator pH 1-2 Range (low– high)

Table B: Cabbage pH Indicator Key pH Range (low–high)

1-2

3-4

5-6

Cabbage Solution Indicator

Red

Pale Pink Light Purple

7

8-9

10-11

12-13

Dark Purple

Blue

Green

Yellow

Table C: Test Solutions Lemon Juice

Hand Sanitizer

Soap/Dishwashing Liquid

Predicted pH

1-2

7

8-9

Cabbage Indicator Color

Red

Purple

Blue

pH Range (low–high)

1-2

7

8-9

Acidic, Basic, or Neutral

Acidic

Neutral

Basic

Analysis- In this lab experiment we learned that you can test the pH of different acids and bases by using a red cabbage water. This is true because looking at the world wide pH color indicator and the colors that the cabbage water brought out in the different substances you can determine what the pH of the substance is and if it is an acid,base or neutral. This is proven with our findings when we mixed Lemon juice with the cabbage water it turned red indicating a low pH meaning it is acidic.

Conclusion- In conclusion, if you compare the worldwide pH indicator to the cabbage water one there are some color differences but using this method to test the pH’s of different substances

still yielded colors similar to the world wide pH color test.You are able to look at the colors and determine what the pH of a substance is....