Question

Difference between true value and observed value is -----

• A. Accuracy
• B. Precision
• C. Error
• D. Endpoint

Hint:

Remember the simple relationship:
- Error = Observed - True.
Accuracy is the inverse of error (high accuracy means low error).
Precision is the consistency among repeated measurements.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
In scientific measurements and analytical chemistry, experimental values are evaluated against accepted reference standards to determine accuracy and precision.

Step 2: Detailed Explanation:
Let us define the terms:
- Error (C): This is defined as the deviation or difference between the experimentally observed (measured) value and the true (accepted reference) value:
\[ \text{Error} = \text{Observed Value} - \text{True Value} \]
Error can be absolute (expressed in the same units as the measurement) or relative (expressed as a percentage of the true value).
- Accuracy (A): This describes how close a measured value is to the true or accepted value.
A lower error indicates higher accuracy.
- Precision (B): This describes the reproducibility or agreement among multiple independent measurements of the same parameter under identical conditions, regardless of how close they are to the true value.
- Endpoint (D): In titrations, this is the physical point at which a color change or indicator change occurs, signaling that the reaction is complete.
Therefore, the difference between the true and observed value is defined as the Error.

Step 3: Final Answer:
The difference between the true value and observed value is Error.