Be careful! The scientist was a bit sloppy again when labeling his containers in the acid and base cabinet. Use your knowledge of acids, bases and the pH value to identify the right liquid!
Materials needed:
- 4 test tubes with unknown liquids
- Universal indicator paper with color scale
- Test tube holder
- Glass rod
Execution of experiment and task:
- You discover the following note in the lab journal: “Important: neutralize solution X! (test tube with required amount was already prepared). Check with indicator paper." But next to the beaker of solution X are 3 test tubes. From class, you know neutralizing has something to do with pH, which has a scale from 1 to 14. Next to the beaker is a yellow strip of paper and a color scale numbered from 1 to 14. That must be this indicator paper.
- Determine the pH value of solution X and the solutions in the test tubes by placing a drop with the glass rod on a piece of indicator paper. Dip the glass rod into a glass of water between each liquid and dry the glass rod with a paper cloth. Record the color and corresponding pH value in the table. Which solutions are acidic, neutral or basic?
- Puzzle: Which test tube neutralizes solution X?
- Verification:
Pour the content of the selected test tube into the beaker for solution X to check the result and measure the pH value of this solution after stirring with the glass rod.
The code is the number on the test tube.