How do you investigate the time taken for a mixture of oil water and emulsifier to separate depending on the volume of emulsifier?
Please include control variables, risk assessment, equipment, measurements ect.
Also I will need two methods and then compare them (which is more reliable etc.)
The scientific method is a process by which scientists solve problems using the things you listed in your question, such as control variables, experimental variables, etc. Your hypothesis could go one of two ways on this experiment. If you think more emulsifier will take less time, you would state it that way. On the other hand, if you think less emulsifier will take more time, you could go that way. You would basically want to design an experiment around the amount of emulsifier used and the amount of time it took to see the desired effect, which would be to disperse the oil into the water. The experimental factor here would be the amount of emulsifier used, while the dependent factor would be the time it took for the emulsifier to take effect. All other variables would be control factors, such as the amount of water, the amount of oil, etc. Either way you decide to go, you should be able to show a relationship between the amount of emulsifier used and the time it took to achieve that result.