Question

S. A 1.000 mL sample of acetone, a
common solvent used as a paint
remover, was placed in a small bottle
whose mass was known to be 38.0015
g. The following values were obtained
when the acetone - filled bottle was
weighed : 38.7798 g, 38.7795 g and
38.7801 g. How would you characterise
the precision and accuracy of these
measurements if the actual mass of the
acetone was 0.7791 g ?
(Ans.: +0.07736% 0.1027%)​

Answer 1

Answer:

Explanation:

Given A 1.000 mL sample of acetone, a

common solvent used as a paint

remover, was placed in a small bottle

whose mass was known to be 38.0015

g. The following values were obtained

when the acetone - filled bottle was

weighed : 38.7798 g, 38.7795 g and

38.7801 g.

We need to check average measurement to actual mass of acetone 0.7791 g. So average of measurement is

0.7783 g + 0.7780 g + 0.7786 g / 3 = 0.7783 g

Now we need to calculate the percentage difference of average measurement to actual mass

Percentage = actual – measured / actual x 100

                    = 0.7791 g – 0.7783 g / 0.7791 g x 100 = 0.102%  

Since there is a very small difference between the measured mass and actual mass, the measurements are accurate.

Answer 2

Answer:

we measure a actual value =0.7780+0.7786+0.7783/3=0.7783

percentage = actual - measured / actual ×100. 0.7791-0.7783/0.7791×100=0.102%