Question

The accepted value for the density of gold metal is 19.31 g/cm^3. If a student measured the mass and volume of a sample of gold, and obtained a value of 19.03 g/cm^3, the percent difference would be ______

(a) -1.5%

(b) 1.5%

(c) -0.5%

(d) 0.5%

The question was asked in quiz.

This question is from Errors in Data and Calculations topic in chapter Presentation and Analysis of Data of Bioprocess Engineering

Answer 1

Correct answer is (a) -1.5%

To elaborate: % difference = [(19.03 – 19.31) g/19.31 g] x 100% = – 1.5%

A percent difference can be positive or negative; the sign shows whether the experimental value is higher or lower than the actual or theoretical value. This distinction is not used in precision since all values are experimental.