In today’s science lesson, we explored an irreversible change. We mixed bicarbonate of soda with vinegar to create a chemical reaction which resulted in the formation of carbon dioxide. 
We then discussed how we could increase the amount of carbon dioxide that was formed and the importance of controlling variables.
- control variables (the variables we kept the same): the size of the bottle, the amount of bicarbonate of soda, the type of balloon):
- independent variable (the variable we changed): the amount of vinegar
- dependent variable (the variable we are testing): the amount of carbon dioxide
We found that increasing the amount of vinegar resulted in the creation of more carbon dioxide. However, the 100ml test (green balloon) didn’t support this finding. Possibly there was too much vinegar or maybe the green balloon made a difference! We discussed how repeating this test would make our date more reliable.