Chapter 20, Problem 20.13P

Interpretation Introduction

Interpretation:

The mass change in g/mol of NaCl for the reaction of sodium metal with chlorine gas to give sodium chloride needs to be determined.

${\text{2 Na}}_{\text{(s)}}{\text{ + Cl}}_{\text{2(g)}}\stackrel{}{\to }{\text{ 2 NaCl}}_{\text{(s) }}\text{ ΔE = - 820 kJ}$

Concept introduction:

In an atom, three sub-atomic particles which are arranged in a certain way to make the atom stable. The nuclear attraction force works between electrons and protons due to opposite charges. The force between protons and neutrons holds these particles together. It can be measured by measuring the amount of energy necessary to break these forces.

It can be calculated with the help of Einstein’s mass − energy equation:

${\text{ΔE= m × c}}^{\text{2}}$

Here, m is mass and c is speed of light.