PRACTICALS SUGGESTIONS Flashcards
Calculating dry mass
Heat at 100C
Weigh and heat until no change in mass
Create anaerobic conditions In a respirometer
Place a layer of oil
Using colorimeter to work out an unkown concentration using calibration curve
Make solutions of known concentrations
Use calorimeter to measure absorbency value of each solution and plot calibration curve
Read off graph to find concentration of unkown
Why do we use controls
To ensure that only x has an effect on y
Why we randomly sample
Prevents bias and ensures dara are representative of the population
Why we collect large number of data
Increases reliability
Allowsuse of statistical tests
Effect of variation in data is minimised
Why repeat results can imporve a graph
Line best fit is more reliable
Allows Plot SD values/ error bars
Why we calculate dry mass
Amount of water present will vary
This effects fresh mass
Improvements example in an experiment
Large sample size
More accurate measurements
Ensure data is not subjective
More repeats
