Today we will focus on Design, Aspect 3.
In order to achieve a ‘c in this aspect, the student must write a detailed method. The emphasis is on the word detailed. The student should essentially be able to give another IB Chemist the method and they would be able to carry it out.
Often, methods are not detailed enough. For example, in a cell reaction lab the student writes ‘connect the voltmeter and record the voltage’ – there is not enough detail in this statement. For example, how does one ensure that the voltmeter is connected the correct way? What happens if the voltmeter records a negative voltage (when the voltage should be positive)?
Another example may be in a kinetics lab where a student is adding magnesium to acid and collecting the hydrogen produced. Statements like ‘add the magnesium and collect the gas evolved’ are again, not detailed enough. The student needs to include details of how to minimise the escape of the gas, how to connect the apparatus, etc.
Students also need to ensure that they are repeating individual tests and changing the independent variable at least five times.