What is the Difference Between Accuracy and Precision in Chemistry?

The difference between accuracy and precision in chemistry lies in how close a measurement is to the true or accepted value and how close a series of measurements are to one another.

• Accuracy: This refers to the closeness of a measured value to a standard or known value. In other words, it is the degree of correctness of a measurement. For example, if you weigh a given substance and obtain a result of 3.2 kg, but the actual weight is 3.1 kg, your measurement is considered accurate because it is close to the true value.
• Precision: This is a measure of how close a series of measurements are to one another. It refers to the degree of exactness or consistency in the results of multiple measurements. If you weigh the same substance five times and get 3.2 kg each time, then your measurement is considered precise because the results are consistent with each other, even if they are not necessarily close to the true value.

It is essential for scientists to strive for both accuracy and precision in their measurements. A precise measurement is highly reproducible, even if it is not near the correct value. On the other hand, a highly accurate measurement may be random if it lacks precision. In a chemistry laboratory situation, high precision with low accuracy often results from systematic errors, such as using a flawed measuring tool or making the same mistake repeatedly. Both accuracy and precision are crucial for obtaining reliable and valid results in scientific experiments.

Comparative Table: Accuracy vs Precision in Chemistry

Here is a table that highlights the differences between accuracy and precision in chemistry:

In summary, accuracy is concerned with how close a measured value is to the true value, while precision is concerned with the level of agreement among a set of results.