Question

An analytic balance has uncertainty In measurement equal to $\pm$1 mg. Then report the result in terms of percentage if the weight of a compound is
(a) 1 g
(b) 10 g
(c) 100 g

• A. ;
• B.
• C.
• D.

Answer 1

The correct option is A

;

(a) $1\pm 0.1\%$ (b) $10\pm 0.01\%$ (c) $100\pm 0.001\%$
The uncertainty in measurement is expressed in terms of percentage by putting $\pm$ sign before it, e.g., $150\pm 1\%$, et. Smaller the quantity to be measured, greater is the percentage uncertainty, and the instrument should be more precise for the measurement of smaller quantities.

$1mg=\frac{1}{1000}g\frac{1}{1000}\times 100=\frac{1}{10}=0.11\pm 0.1\%$