Loading…
Loading…
GCSE Chemistry · key term
How close a measured value is to the true value.
Used by AQA, Edexcel and OCR
Specification 4.8.3.6 · Paper 2
The closeness of a measured result to the true value.
Revise: Instrumental AnalysisIn such situations, sensitivity helps detect the small sample, accuracy supports a dependable conclusion and rapid analysis supplies the result without unnecessary delay.
Specification 9.8C · Paper 2
Do not confuse accurate with rapid: accuracy concerns how close a result is to the true value; rapid means the analysis can be completed quickly.
Do not confuse sensitivity with accuracy. Sensitivity concerns detecting small quantities or changes, whereas accuracy concerns closeness to the accepted value.
If asked for advantages of instrumental analysis, name sensitivity, accuracy and speed, then explain what each means.
Create a free account to read GCSE Chemistry revision notes for your exam board and track your progress.
How close a measured result is to the true or accepted value.
Accuracy describes how close a measurement is to the true or accepted value. Visual judgements can vary between people: two observers might describe the same weak colour differently. An instrument can measure a signal numerically rather than relying only on a person’s judgement.
Specification C4.2f, PAG 6, PAG 8 · Paper 1 (Foundation), Paper 2 (Foundation), Paper 3 (Higher), Paper 4 (Higher)
How close a measured result is to the true or accepted value.
Revise: Instrumental AnalysisInstrumental methods are particularly valuable when a sample is tiny, many samples must be analysed, or a measurement must be made more objectively than is possible by eye. Their three central advantages are sensitivity, accuracy and speed.
A result close to the accepted or true value.
Paper 1 (Foundation), Paper 2 (Foundation), Paper 3 (Higher), Paper 4 (Higher)
How close a measured result is to the true value.
Revise: Advantages of instrumental methodsSensitivity and accuracy answer different questions: can the substance be detected? and how close is the result to the true value?
How close a measurement is to the true value.
How close a measured value is to the true or accepted value.
How close a measurement is to the true or accepted value.
The closeness of a measured value to the true value.