Purpose: Use Table M and various indicators to determine the pH of acetone
Equipment: Test tubes, test tube rack, acetone, various indicators, tweezers
Procedure:
1. Fill each test tube with a few drops of acetone
2. Put 2 drops of an indicator into 1 of the test tubes
3. Record color change
4. Determine the pH range based on the color change using Table M and record data
5. Repeat for each indicator
6. To test litmus, dip red and blue litmus into acetone and determine pH based on color change
Data:
|Indicator |Color in test tube |Indicator pH color range |Determined pH range based on color |
|Methyl Orange |Yellow |Red to yellow |pH > 4.4 |
|Bromthymol Blue |Yellow |Yellow to blue |pH < 6 |
|Litmus |No color change |Red to blue |4.5 < pH < 8.3 |
|Methyl Red |Orange |Red to yellow |4.4 < pH < 6.0 |
|Phenolphthalein |Clear |Yellow to blue |pH < 8 |
Conclusion: I think the pH range of acetone is 4.5 < pH < 6.0. Since the test tube turned yellow when methyl orange was added, the pH must be greater than 4.4. The bromthymol blue has a color range of yellow to blue and pH range of 6.0 to 7.6. Since the test tube with bromthymol blue turned yellow, pH is less than 6.0. When phenolphalein was added to a test tube containing acetone, it remained clear. This means the pH must be less than 8. The litmus paper had no color change, meaning the pH range was between 4.5 and 8.3. The methyl red turned the test tube