University:
Eastern Kentucky University
Course:
CHE 111 | General Chemistry
Academic year:

2022
Views:

251

Pages:

3
Author:

jaxbrokenhart4z4x

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.