Uncertainties in measurements: chemistry | Exit Quiz | Oak National Academy

What does the uncertainty of a measurement indicate?

• The exact value of the measurement.

• The precision of the apparatus.

• The range within which the true value can be found.

• The number of measurements taken.

Answer explanation

Uncertainty provides a range suggesting where the true value likely resides, acknowledging the inherent limitations of our measuring tools.

Match the term to its correct definition.

• Measurement

• A piece of equipment designed for a particular use.

• Resolution

• An average calculated from a set of values.

• Mean

• The smallest change a piece of apparatus can measure.

• Uncertainty

• The range within which the true value can be found.

• Apparatus

• Quantitative information about an object or system.

Answer explanation

Each term directly corresponds to fundamental concepts in scientific measurements and calculations.

How does a higher resolution affect the uncertainty of a measurement?

• Increases the uncertainty.

• Decreases the uncertainty.

• Has no effect on uncertainty.

• Makes the measurement less accurate.

Answer explanation

Higher resolution means the apparatus can measure smaller changes, thus reducing the uncertainty and making measurements more precise.

___ is the range of measurements within which the true value can be expected to be found. It reflects the limitations of our measuring devices.

Answer explanation

Uncertainty is the range of measurements within which the true value can be expected to be found. It reflects the limitations of our measuring devices.

The resolution of a measuring device is 0.02 g. What is the uncertainty of an individual measurement?

• 0.01 g

• 0.02 g

• 0.04 g

• 0.1 g

Answer explanation

The uncertainty of an individual measurement is half the resolution of the device, making it 0.01 g.

Why is it important to consider the choice of equipment when conducting measurements?

• Equipment choice has no impact on the outcome.

• Different equipment can yield different levels of precision.

• Better equipment always guarantees the correct value.

• Equipment choice affects the colour of the data.

Answer explanation

Choosing the right equipment, particularly one with an appropriate resolution for the measurement, can significantly impact the precision and accuracy of the data collected.