Year 9 recently took part in a practical science lesson in the school lab. The aim was to find which number on the pH scale will various acids and alkalis be after universal indicator is added.
A large part of this experiment was planning and preparation in the classroom. The pupils needed to understand the process for completing the experimenting and how they would be able to form a conclusion.
Predictions were made about the pH level that each solution might change to once the universal indicator was added.
The first thing we did in the lab was to find our safety goggles and make sure our work stations were clear. Four solutions were tested: lime juice, vinegar, baking soda and lime water.
Our method involved 1cm of each solution being added to a test tube using a pipette. We had to keep this amount constant to make it a fair experiment. Each test tube was labelled.
The universal indicator was then added. The Year 9 students were asked to observe the change in colour. This was then matched up with the pH scale in our books to show the strength of change.
The results were logged in our science books. The students were then asked to form a conclusion about the level of change for each solution.