Frank Marken

Question 1

What is proportional error?

Answer 1

Uncertainty depends on the size of the sample

Question 2

What is constant error ?

Answer 2

The error doesn’t depend on the size of the sample

Question 3

What is a random error

Answer 3

Causes scatter about the true value

Question 4

What is a systematic error

Answer 4

Affects all readings in the same way

Question 5

Contrast the principles and applications of the t-test and the Q-test

Answer 5

Qtest based on the assumption of a true random error. Evaluation of potential outliers and self consistency of data sets
T test based on the assumption of true random error. Comparison of 2 data sets. Statistical significance of differences given the standard deviation.

Question 6

What could cause a systematic error?

Answer 6

Incomplete dissolution 
Poor drying 
Wrong reagent concentrations
Poor technique
Incorrect instrument settings 
Wrong calibrations

Question 7

What could cause a random error?

Answer 7

Is meniscus on the mark
Temperature
Draughts 
Angle of holding the pipette
Drainage time
Underlying natural fluctuation

Question 8

What is AFS

Answer 8

Secondary emission lines are possible after excitation into a higher electronic state and rapid decay or collision induces changes before emission