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{
"metadata": {
"name": ""
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 1: Bonding in Solids"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 1.1, Page number 1.4"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"from math import pi\n",
"\n",
"#Variable declartion\n",
"E_a = 502 #first ionization energy of A(kJ/mol)\n",
"E_b = -335 #electron affinity for B atom(kJ/mol)\n",
"d = 3*10**-10 #inter-ionic seperation(m)\n",
"E = 8.85*10**-12 #permittivity of free space(C/N -m)\n",
"e = 1.602*10**-19#charge of an electron(C)\n",
"\n",
"#Calculations\n",
"C_e = (-e**2)/(4*pi*E*d) #Coulumbic attraction energy(J/ion pair)\n",
"C_e_kj = C_e *6.022*10**23*10**-3 #Converting C_e to KJ/mol\n",
"n_e = E_a + E_b + C_e_kj #Net change in energy per mole\n",
"\n",
"#Results\n",
"print \"Net change in energy is =\",round(n_e,3),\"kJ/mol\"\n",
"print \"As the net change in energy is negative, the molecule will be stable\"\n",
"print \"\\nThe solution differs because of rounding-off of the digits in the textbook\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Net change in energy is = -296.224 kJ/mol\n",
"As the net change in energy is negative, the molecule will be stable\n",
"\n",
"The solution differs because of rounding-off of the digits in the textbook\n"
]
}
],
"prompt_number": 19
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 1.2, Page number 1.4"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"from math import pi \n",
"\n",
"#Variable declaration\n",
"IP_K = 4.1 #ionization energy of K(eV)\n",
"EA_Cl = 3.6 #electron affinity of Cl(eV)\n",
"e = 1.602*10**-19 #charge of an electron(C)\n",
"Eo = 8.85*10**-12 #permittivity of free space(C/N -m)\n",
"\n",
"#Calcuations\n",
"del_E = IP_K - EA_Cl\n",
"#Ec = 0.5 = -e/4*pi*Eo*R\n",
"R = e/(4*pi*Eo*del_E)\n",
"\n",
"#Results\n",
"print \"(a) If their total energy is to be zero, then del_E = Ec\"\n",
"print \"(b) The seperation between the ion pair is\", round((R/1E-9),2), \"nm\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"(a) If their total energy is to be zero, then del_E = Ec\n",
"(b) The seperation between the ion pair is 2.88 nm\n"
]
}
],
"prompt_number": 7
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 1.3, Page number 1.5"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"from math import pi\n",
"\n",
"#Variable declaration\n",
"ro = 2.36*10**-10 #inter ionic equilibrium distance(m)\n",
"IP = 5.14 #ionization energy of Na(eV)\n",
"EA = 3.65 #electron affinity of Cl(eV)\n",
"e = 1.602*10**-19 #charge of an electron(C)\n",
"Eo = 8.85*10**-12 #permittivity of free space(C/N -m)\n",
"\n",
"#Calculations\n",
"Ue = (-e**2)/(4*pi*Eo*ro*e) #Potential energy in eV\n",
"Be = -Ue - IP + EA\n",
"\n",
"#Result\n",
"print \"Bond energy for NaCl molecule is\",round(Be,2),\"eV\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Bond energy for NaCl molecule is 4.61 eV\n"
]
}
],
"prompt_number": 9
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 1.4, Page number 1.18"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"from math import pi\n",
"\n",
"#Variable declaration\n",
"ro = 0.281*10**-9 #equilibrium seperation between the ion pair(m)\n",
"IP = 5.14 #ionization energy of Na(eV)\n",
"EA = 3.61 #electron affinity of Cl(eV)\n",
"A = 1.748 #Madelung constant\n",
"n = 9. #born replusive exponent\n",
"e = 1.602*10**-19 #charge of an electron(C)\n",
"Eo = 8.85*10**-12 #permittivity of free space(C/N -m)\n",
"\n",
"#Calculations\n",
"Ce = (A*(e**2)*(1-(1/n)))/(4*pi*Eo*ro) #joules\n",
"Ce_ev = Ce/e #Converting joules to eV\n",
"\n",
"#Result\n",
"print \"The cohesive energy of NaCl molecule is\",round(Ce_ev,2),\"eV\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The cohesive energy of NaCl molecule is 7.97 eV\n"
]
}
],
"prompt_number": 22
}
],
"metadata": {}
}
]
}
|
