Perform an experiment to demonstrate the effect of dissolved carbon dioxide on the PH of water.
AIM: To demonstrate the effect of dissolved carbon dioxide on the PH of water
HYPOTHESIS: Dissolved carbon dioxide in water affects the PH level. Therefore dissolved (co2) decreases the PH of water
· PH probe
· Data logger
· 250ML beaker
· Distilled water
· Universal indicator
When carbon dioxide is added to limewater it causes the precipitation of the white compound calcium carbonate causing the limewater to become milky/cloudy. This is used to test for the presence of carbon dioxide, and also by using universal indicator which changes colours in acids and alkalis.
The independent variable in this experiment is the amount of dissolved Co2, whereas the dependent variable is the PH of the water. The controlled variable is the size of the beaker, the same intensity of breaths, the size of the straw, the same amount of water etc.
The control in the experiment is that there was no Co2 added to the water.
PART A OF EXPERIMENT:
The 250ML beaker was filled with water halfway. One squirt of limewater was added after that and carbon dioxide was dissolved...