Unit 2, Topic 4 - Concept Check (Precision, Accuracy, % Error)

When a set of measurements (multiple measurements) are close to each other

• Precision

• Accuracy

When a single measurement is close to an accepted value

• Precision

• Accuracy

% error can be a positive or negative value.

• Yes

• No

2.34 g, 2.33 g, 2.35 g, 2.34 g

• These values show precision.

• These values show accuracy.

Experimental Value = 25 °C. Accepted Value = 26 °C

• These values show precision.

• These values show accuracy.

Calculation!!

If the accepted value of a measurement is 11.4 g and the experimental value of the measurement 11.0 g, what is the % error?

• 3.51 % error

• -85.1 % error

• -3.63 % error

What are 2 sources of error in taking measurements?

• human error and instrumentation error

• physical error and chemical error

• alpha error and omega error

A measurement that doe not "fit in" with other measurements of the same type

• outlier

• inlier

• exlier

Calculation!!

If the experimental value of a measurement is 9.5 mL and the accepted value of the measurement 9.0 mL, what is the % error?

• -5.6 % error

• 794% error

• 5.3 % error

% error is an indication of _____.

• precision

• accuracy