In science we have been learning about acids and bases. We have done several experiments that involve acids and bases. One of these identifying acids and bases and where they are in the pH scale.
The experiment used Anthocyanin (red cabbage water), diluted acetic acid (vinegar), baking soda, citric acid and lemon juice. The experiment consisted of adding vinegar, baking soda, citric acid or lemon juice to the Anthocyanin. Anthocyanin is an indicator meaning if a base was added it would become blue and if a acid was added it would become red/pink. The second experiment consisted of putting vinegar and baking soda in a film canister before closing the lid tightly. If successful the canister would pop and soar up from the build up of pressure from the acid based reaction between the baking soda and vinegar. In both experiments we had to be precise with measurements.
The most recent experiment we did was use pH indicator paper and a machine that measures pH levels borrowed from Williams mum to determine the pH of various items students brought in. These items included: coke, salt water, lemon concentrate, soda water, diluted zinc powder, lime juice and window cleaner.
We also learnt about scientific terms such as variables and fair tests.
Independent Variables: Independent Variables are what you chose to change in the experiment.
Dependent Variable: What you measure or observe.
Controlled Variables: The things you do not change in the experiment.
Fair Tests: To create a Fair Test you only change one factor at a time in an experiment while keeping everything else the same.