Uncertainty

Question 1

What is a reading

Answer 1

The values found from a single judgement when using a piece of equipment

Question 2

What is a measurement

Answer 2

Values taken as the difference between the judgement of two values

Question 3

What is the assumption made for the uncertainty of a reading for an ANALOGUE scale

Answer 3

at least +/- 0.5 of the smallest scale reading

Question 4

What is the assumption made for the uncertainty of a measurement for an ANALOGUE scale

Answer 4

at +/- 1 of the smallest scale reading

Question 5

What is the assumption made for the uncertainty if the apparatus has a digital scale

Answer 5

+/- the resolution of the apparatus in each measurement

Question 6

How can you decrease apparatus uncertainties

Answer 6

Decrease sensitivity uncertainty by using apparatus with greater resolution (finer scale divisions)

Increase size of measurement made

Question 7

How do you reduce percentage uncertainty in a burette reading

Answer 7

Make the titre a larger volume by :

Increasing volume and concentration of substance in conical flask
Decreasing concentration of substance in the burette

Question 8

How to reduce uncertainty in measuring mass

Answer 8

Use a balance that measures to more decimal places or use a larger mass

Question 9

How do you get a more accurate measurement of the solid added

Answer 9

Weighing the sample before and after addition and then calculating the difference