Chapter 9, Problem 9.15QAP

Interpretation Introduction

(a)

Interpretation:

At higher temperature rate, transition of atoms of sodium occurs from 4s to 3p state and the average wavelength of sodium due to the emission is 1139 nm. Ratio of excited state 4 seconds to ground state 3seconds needs to be calculated for acetylene- oxygen flame of 3000^oC.

Concept introduction:

Calculation of ratio is done by using the Boltzmann equation, given as-

$\frac{N_j}{N_o}=\frac{g_j}{g_o}\exp \left(\frac{-E_j}{kT}\right)$

Where,

N_j = no. of ions in excited state

N_o = no. of ions in ground state

Ej = energy difference of excited state and ground state

g_j = statistical weight for excited state

g_o = statistical weight for ground state

k= Boltzmann constant

T = absolute temperature

Energy of atom is calculated by the following formula-

$E_j=\frac{hc}{\lambda }$

Where,

h= Planck’s constant

c = light velocity

λ= wavelength

Ej= energy difference

Interpretation Introduction

(b)

Interpretation:

Ratio of excited state 4s to ground state 3s needs to be calculated for an inductively coupled plasma source of 9000^oC.

Concept introduction:

Calculation will be done using the following formulas-

$\frac{N_j}{N_o}=\frac{g_j}{g_o}\exp \left(\frac{-E_j}{kT}\right)$    ......(1)

And

$E_j=\frac{hc}{\lambda }$    ......(2)