Question

A Class-A 10 mL pipette is supposed to dispense 10.00 mL of water. A lab technician makes three measurements of the volume that the pipette actually dispenses, and obtains volumes of 9.70 mL, 9.69 mL, and 9.71 mL. The pipette is:__________
a) Accurate, but not precise
b) Precise, but not accurate
c) Accurate and precise
d) Neither accurate or precise

Answer 1

Answer:

d) Neither accurate or precise

Explanation:

Accuracy and precision are critical factors in the experimental procedure. Accuracy can be defined as the amount of uncertainty in the process of measurement in relation to the true value (in this case, 10 mL). On the other hand, precision is an independent feature of the accuracy which indicates the repeatability of the measurement process (in this case, three measures weren't repeated). Therefore, precision indicates the confidence of a particular measurement, while accuracy indicates how close is this value to the real value.