Question

1. the following measurements were made to determine the density of a material whose value was, according to the handbook of chemistry and physics, 1.24 g/ml

trial #1
1.20 g/ml
trial #2
1.22 g/ml
trial #3
1.22 g/ml

a. make a general comment on the accuracy of these results
b. make a general comment on the precision of these results

Explanation:

a. Accuracy is closeness to the true value (1.24 g/mL). Measured values (1.20, 1.22, 1.22) are all lower, so low accuracy.
b. Precision is consistency of measurements. The three values are close (differences ≤0.02), so high precision.

Answer:

a. The results have low accuracy as they are all below the handbook value (1.24 g/mL).
b. The results have high precision as the measured values are consistent (differences ≤0.02 g/mL).