Errors & Uncertainties in Chemistry - Diner

Solve the following equation: 14.28 + 5.13 + 2.2222

• 21.6

• 21.63

• 21.632

• 21.6322

The first length measured in a laboratory experiment is 2.5 + 0.1 m and the second length 3.4 + 0.1 m. What is the uncertainty of the sum of the lengths?

• 0.1 m

• 0.2 m

• 0.3 m

• 0.4 m

To propagate two uncertainties for length measured in millimetres, you should....

• Add them together

• Take the difference between them

• Calculate a percentage uncertainty

• Calculate a fractional uncertainty

A measurement result is considered ________ if it is judged to be close to the true value. It is influenced by random and systematic errors.

• Precise

• Accurate

• An error

• Resolution

A quality denoting the closeness of agreement (consistency) between values obtained by repeated measurement. It is influenced by random effects and can be expressed numerically.

• Repeatability

• Precision

• Uncertainty

• Resolution

Any measurement will have some ____________. This will come from variation in the data obtained and be subject to systematic or random effects. This can be estimated by considering the instruments and the method and will usually be expressed as a range such as 20 ± 2 °C.

• Error

• Precision

• Reproducibility

• Uncertainty

When you multiply or divide two quantities, you...

• add the percentage uncertainties

• subtract the percentage uncertainties

• add the absolute uncertainties

A student measures the acceleration due to gravity as 9.0m/s² ±10%. Is this answer valid within the experimental uncertainty?

• Yes

• No

Which of the following is an example of qualitative data:

• 6 red fish, and 8 black fish

• An orange roughy that's 25 years old

• 8 billion metric tons of bycatch

• The bycatch consisted of dolphins, turtles, and jellyfish

Systematic errors lead to a lack of:

• accuracy in the measurement.

• significant digits in the measurement.

• precision in the measurement.

• gradation of the measuring instrument