A student performed Benedict’s test on four glucose solutions of different concentrations and then noted the time taken until the colour first changed (the end-point). The student was unable to judge the very first sign of a colour change and therefore timed each solution for 2 seconds after the change had already begun. This added a source of error to the investigation. Which statements about this error are correct?
- A1 and 2
- B1 and 3
- C2 and 3
- D3 only