Chapter 3, Problem 3.21P

Interpretation Introduction

Interpretation:

The molecular mass $(\pm \text{uncertainty)}$ of ${\text{C}}_{\text{9}}{\text{H}}_{\text{9}}{\text{O}}_{\text{6}}{\text{N}}_{\text{3}}$ with the correct number of significant figures has to be expressed.

Concept Introduction:

Uncertainty:

Uncertainty means state of not certain in predicting a value.  In a measured value, the last digit will have associated uncertainty. Uncertainty has two values, absolute uncertainty and relative uncertainty.

Absolute uncertainty:

Expressed the marginal value associated with a measurement

Relative uncertainty:

Compares the size of absolute uncertainty with the size of its associated measurement

$\text{Relative uncertainty = }\frac{\text{absolute uncertainty}}{\text{magnitude of measurement}}$

To Express: The molecular mass $(\pm \text{uncertainty)}$ of ${\text{C}}_{\text{9}}{\text{H}}_{\text{9}}{\text{O}}_{\text{6}}{\text{N}}_{\text{3}}$ with the correct number of significant figures