% uncertainty/error

Question 1

What is the equation for % uncertainty?

Answer 1

% uncertainty = ((error on equip x no of measurement taken)/quantity measured ) x 100

Question 2

What is the % uncertainty of a 100cm^3 measuring cylinder and the number of measurements used?

Answer 2

+- 1.0cm^3

1

Question 3

What is the % uncertainty of a 50cm^3 measuring cylinder and the number of measurements used?

Answer 3

+- 0.5cm^3

1

Question 4

What is the % uncertainty of a 25cm^3 measuring cylinder and the number of measurements used?

Answer 4

+- 0.25cm^3

1

Question 5

What is the % uncertainty of a 25cm^3 pipette and the number of measurements used?

Answer 5

+- 0.06cm^3

1

Question 6

What is the % uncertainty of a 50cm^3 burette (0.1cm^3 graduation) and the number of measurements used?

Answer 6

+- 0.05cm^3

2

Question 7

What is the % uncertainty of a 2d.p mass balance and the number of measurements used?

Answer 7

+- 0.01g

2

Question 8

How do you reduce % uncertainty?

Answer 8

1. increase the quantity measured

2. use a more precise equipment