Our experiment is to investigate the rates of reaction when we use different citric acid amounts with red cabbage. We will be timing how long it takes for the water to change from purple to pink when we add lemon, Berocca and orange.
Materials needed:
1 cup chopped red cabbage
20ml freshly squeezed lemon juice
20ml freshly squeezed orange juice
One Berocca tablet
150ml water
Kettle
Timer
3 glasses
Method:
You will need to copy this table to record your results.
Hypothesis:
The higher the level of citric acid that mixes with the cabbage, the faster the rate of reaction.
What are our variables in our experiment?
Independent variables: we change the concentration of citric acid we use.
Dependent variable: the time it takes for the liquid to change colour is dependant on the concentration of citric acid we use.
Control variable: we use 20ml of each food and 60ml of purple water for each experiment.
Testing:
Results:
Conclusion:
As we thought in our hypothesis, the higher the citric acid levels the faster the rate of reaction.
There was only a 0.26-second difference between the Lemons reaction and Oranges reaction. The Lemon reacted a little bit faster because it has more citric acid than an orange.
The Berocca tablet took much less time than the other two fruits. It took 1 second to change the water from purple to pink and this is because the citric level of one tablet is 46.4%, which is much higher than both the lemon and orange.
The tablet continued to fizz for another minute and 50 seconds but we only want the results for how fast it takes to change the water colour.
To get a more diverse set of results next time we should use food that has a much higher amount of citric acid that a lemon but not as much as a Berocca tablet.
In conclusion, our hypothesis was correct and the higher amount of citric acid we used, the faster it took for the water to change colour.