1. Aim
The aim of this experiment was to test different household chemicals to find out whether they were acidic, neutral, or basic. We used Universal Indicator and litmus paper to see how the chemicals changed colour and determine their pH.
2. Equipment
- Universal Indicator
- Litmus paper
- Test tubes or containers
- Droppers
- Household chemicals
- Safety goggles
- Water
- Paper towels
3. Method
- Put on safety goggles.
- Label a container for each household chemical.
- Add a small amount of each chemical to its labelled container.
- Add a few drops of Universal Indicator to each chemical.
- Observe the colour change and record the results.
- Dip litmus paper into each chemical.
- Record whether the litmus paper changed colour.
- Compare the results from the Universal Indicator and litmus paper.
- Use the colour changes to identify whether each chemical was acidic, neutral, or basic.
4. Results
5. Discussion
Why did different household chemicals change different colours?
Different household chemicals contain different types and amounts of ions. Acids have more hydrogen ions (H⁺), while bases have more hydroxide ions (OH⁻). These ions cause the Universal Indicator to change different colours depending on the pH of the chemical.
How did you know if the chemicals were acidic or basic using Universal Indicator?
I compared the colour of each chemical to the Universal Indicator pH scale. Red, orange and yellow showed that the chemical was acidic, green showed it was neutral, and blue or purple showed that it was basic.
How did you know using litmus paper?
Blue litmus paper turns red when it is placed in an acid, while red litmus paper turns blue when it is placed in a base. This allowed us to identify whether a chemical was acidic or basic.
Why might Universal Indicator be more useful than litmus paper?
Universal Indicator can be more useful because it gives an approximate pH, while litmus only tells us if something is acidic or basic. This means we can compare how acidic or basic different chemicals are.
6. Conclusion
Most of my experiments worked because the Universal Indicator and litmus paper changed colour as expected. If some results did not work, it could have been because the chemicals were contaminated or I used different amounts of indicator.
Next time, I could improve my experiment by using the same amount of each chemical and indicator each time. I could also repeat each test several times to make my results more reliable and check that I get similar results each time.