Chapter 6, Problem 12A

Interpretation Introduction

Interpretation: The average mass of 1 atom of bromine in grams needs to be determined.

Concept Introduction: The molecular mass of compound is the sum of atomic mass of all the atoms present in the given chemical compound. Mole concept is used to calculate the moles, mass, number of atoms and moles of a compound. The relation between these values can be shown as:

  $\begin{array}{l}\text{Moles = }\frac{\text{mass}}{\text{molar mass}}\\ {\text{1 mole = N}}_{\text{a}}\text{ atoms}\\ {\text{N}}_{\text{a}}\text{ = 6}\text{.022 }\times {\text{ 10}}^{\text{23}}\end{array}$

Answer to Problem 12A

1 atom of Br = $13.3{\text{ ×10}}^{\text{-23}}\text{ g}$

Explanation of Solution

Given information:

Number of Br atoms = 1

Molar mass of Br = 79.9 g/mol

1 mole = 6.022 x 10²³ atoms

Calculate mass of 1 Br atom:

  $\text{1 Br atom ×}\frac{\text{1 mole}}{\text{6}{\text{.022×10}}^{\text{23}}\text{atoms}}\text{×}\frac{\text{79}\text{.9 g}}{\text{1 mole}}=13.3{\text{ ×10}}^{\text{-23}}\text{ g}$