{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 7:Statistical Thermodynamics" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.1,Page number:193" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "N=20 \t\t\t\t#no, of particles\n", "N1=4 \t\t\t\t#no. of particles in E1 energy level\n", "N2=4 \t\t\t\t#no. of particles in E2 energy level\n", "N3=6 \t\t\t\t#no. of particles in E3 energy level\n", "N4=3 \t\t\t\t#no. of particles in E4 energy level\n", "N5=3 \t\t\t\t#no. of particles in E5 energy level\n", "import math\n", "\t\n", "Nf=math.factorial(N) \n", "N1f=math.factorial(N1) \n", "N2f=math.factorial(N2) \n", "N3f=math.factorial(N3) \n", "N4f=math.factorial(N4) \n", "N5f=math.factorial(N5) \n", "n=N1f*N2f*N3f*N4f*N5f \n", "W=Nf/n \t\t\t#no. of ways of distributing\n", "print\"The no. of ways of distributing the particles is\",W" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The no. of ways of distributing the particles is 162954792000\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.2,Page number:194" ] }, { "cell_type": "code", "collapsed": false, "input": [ "T=298.0 \t\t\t#Temperature [K]\n", "v=6.5*10**13 \t\t#Frequency in [sec-1]\n", "\t#Consider zero point energy = 0.\n", "h=6.627*10**-34 \t#planck's constant[J.s]\n", "k=1.381*10**-23 \t#Boltzmann constant \n", "N=1.0 \t\t\t#Since N=summation(gj*exp(-Ej/kT))\n", "\n", "E1=h*v \t\t\t#for energy level 1[J]\n", "E2=2*h*v \t\t#for energy level 2[J]\n", "x=k*T \n", "g1=1.0 \n", "g2=1.0 \n", "import math\n", "N1=(g1*math.exp(-E1/x)) #molecules present in energy level 1\n", "N2=(g2*math.exp(-E2/x)) #molecules present in energy level 2\n", "n1=N1/N \t\t#fraction of molecules present in energy level 1\n", "n2=N2/N \t\t#fraction of molecules present in energy level 2\n", "print\"The fraction of molecule s present in energy level 1 is\",'{0:.7f}'.format(round(n1,7)) \n", "\n", "\n", "print\"The fraction of molecules present in energy level 2 is\",round(n2,10) \n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The fraction of molecule s present in energy level 1 is 0.0000285\n", "The fraction of molecules present in energy level 2 is 8e-10\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.3,Page number:194" ] }, { "cell_type": "code", "collapsed": false, "input": [ "dE=4.3*10**-20 \t\t\t#difference in energy levels[J]\n", "T1=0.000001 \t\t\t#Initial Temperature[K](approximately zero , needed for \t\t\t\texecution)\n", "T2=300 \t\t\t\t#Final Temperature[K]\n", "k=1.381*10**-23 \t\t#Boltzmann constant [J/K]\n", "import math\n", "\t\n", "x1=k*T1 \n", "r1=math.exp(-dE/x1) \n", "x2=k*T2 \n", "r2=math.exp(-dE/x2) \n", "print\"The ratio of no. of particles per state at 0K is\",r1 \n", "print\"The ratio of no. of particles per state at 300K is\",round(r2,6) " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The ratio of no. of particles per state at 0K is 0.0\n", "The ratio of no. of particles per state at 300K is 3.1e-05\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.4,Page number:195" ] }, { "cell_type": "code", "collapsed": false, "input": [ "T1=273.0 \t\t\t\t#[K]\n", "T2=14273.0 \t\t\t#[K]\n", "E1=-13.6 \t\t\t#Energy of ground state [eV]\n", "k=8.617*10.0**-5.0 \t\t\t#Boltzmann constant[eV/K]\n", "g2=8.0 \t\t\t\t#total no. of states with energy E2\n", "g1=2.0 \t\t\t\t#total no. of states with energy E1\n", "import math\n", "\t\n", "E2=E1/(2.0**2) \t\t#Energy for n=2 (i.e.E2=E1/n2)\n", "x1=k*T1 \n", "r1=(g2/g1)*math.exp(-(E2-E1)/x1) \n", "x2=k*T2 \n", "r2=(g2/g1)*math.exp(-(E2-E1)/x2) \n", "print\"The fraction of atoms present in level n=2 at 273K is\", round(r1,190) \n", "print\"Therefore total 3*10**25 atoms we say that all are present at ground state\" \n", "print\"\\n\\nThe fraction of atoms present in level n=2 at 14273 is\",round(r2,3) \n", "x=r2*3.0*10**25.0 \n", "print\"Therefore no. of atoms in level n=2 is\",x \n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The fraction of atoms present in level n=2 at 273K is 1.97e-188\n", "Therefore total 3*10**25 atoms we say that all are present at ground state\n", "\n", "\n", "The fraction of atoms present in level n=2 at 14273 is 0.001\n", "Therefore no. of atoms in level n=2 is 3.0021673634e+22\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.5,Page number:195" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "r1=0.001 \t\t\t#the population of the states at a higher energy to that at a \t\t\t\tlower energy \n", "dE=8*10**-20 \t\t\t#The difference in energy[J]\n", "k=1.381*10**-23 \t\t\t#Boltzmann constant [J/K]\n", "\n", "\n", "x=k*math.log(r1) \n", "T=-dE/x #[K]\n", "print\"The Temperature at this condition is\",round(T,1),\"K\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The Temperature at this condition is 838.6 K\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.6,Page number:196" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "w=1 \t\t\t#no. of ways of distributing the molecules\n", "k=1.381*10**-23 \t#Boltzmann constant[J/K]\n", "import math\n", "\t\n", "S1=k*math.log(w) \t\t#Entropy of system at 0K\n", "print\"The Entropy of System at 0K and non-degenerate eng level is\",S1,\"J/K/mol\"\n", "\n", "n=2 \n", "R=8.314 #Universal gas constant[J/K/mol]\n", "\n", "S2=R*math.log(n) #Entropy of the system[J/K/mol]\n", "print\"\\nThe Entropy of system at 0K and degenerete eng level is\",round(S2,2),\"J/K/mol\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The Entropy of System at 0K and non-degenerate eng level is 0.0 J/K/mol\n", "\n", "The Entropy of system at 0K and degenerete eng level is 5.76 J/K/mol\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.9,Page number:202" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "V=0.001 \t\t\t#Volume of vessel[m3]\n", "T=300 \t\t\t\t#Temperature [K]\n", "k=1.381*10**-23 \t\t#Boltzmann constant[J/K]\n", "mol_wt=32 \t\t\t#molecular mass of oxygen molecule\n", "h=6.626*10**-34 \t\t#planck's constant[J.s}\n", "\n", "\n", "\t\n", "m=32*1.66*(10**-27) \t\t#mass of oxygen molecule[Kg]\n", "x=((2*3.14*m*k*T)**(3.0/2.0))*V \n", "y=h**3 \n", "zt=x/y \t\t\t\t#Transitional partition function of an oxygen molecule\n", "print\"The Transitional partition function of an oxygen molecule confined in a 1-litre vessel at 300K is\",zt\n", "print\"Wrongly calculated in book as 5.328*10^33\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The Transitional partition function of an oxygen molecule confined in a 1-litre vessel at 300K is 1.76621948031e+29\n", "Wrongly calculated in book as 5.328*10^33\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.12,Page number:204" ] }, { "cell_type": "code", "collapsed": false, "input": [ "R=1.99 \t\t\t#Universal gas constant [cal/K]\n", "e=2.718 \n", "V=22414 \t\t#volume[cm3]\n", "L=6.023*10**23 \n", "h=6.626*10**-27 \t#Planck's constant [erg.sec]\n", "m=6.63*10**-23 \t\t#mass[gm]\n", "k=1.381*10**-16 \t#Boltzmann constant[erg/K]\n", "T=273.2 \t\t#Temperature[K]\n", "import math\n", "\t\n", "x=V*(e**2.5) \n", "y=L*(h**3) \n", "z=(2*3.14*m*k*T)**1.5 \n", "S=R*math.log(x*z/y) #Entropy [cal/degree/mol]\n", "print\"The Entropy of argon at 273K and 1 atm is\",round(S,1),\"cal/degree/mol\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The Entropy of argon at 273K and 1 atm is 36.6 cal/degree/mol\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.14,Page number:207" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "T=298 \t\t\t\t#Temperature[K]\n", "I=1.9373*10**-46 \t\t#moment of inertia of O2 gas [Kg/m2]\n", "h=6.626*10**-34 \t\t\t#Planck's constant[J.s]\n", "k=1.381*10**-23 \t\t\t#Boltzmann constant[J/K]\n", "R=8.314 \t\t\t#Universal gas constant[J/K/mol]\n", "u=2 \t\t\t\t#Homonuclear diatomic molecule\n", "import math\n", "\t\n", "Sr=R+R*math.log(8*3.14*3.14*I*k*T/(u*h*h)) #[J/K/mol]\n", "Gr=-R*0.001*T*math.log(8*3.14*3.14*I*k*T/(u*h*h)) #[KJ/mol]\n", "print\"The rotational entropy for O2 gas is\",round(Sr,3),\"J/K/mol\"\n", "print\"The rotational free energy for O2 gas is\",round(Gr,3),\"KJ/mol\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The rotational entropy for O2 gas is 43.826 J/K/mol\n", "The rotational free energy for O2 gas is -10.583 KJ/mol\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.15,Page number:208" ] }, { "cell_type": "code", "collapsed": false, "input": [ "T=298 \t\t\t\t#Temperature[K]\n", "v=892.1*3*10**10 \t\t#frequency[sec-1]\n", "h=6.626*10**-27 \t\t#Planck's constant [J.s]\n", "k=1.381*10**-16 \t\t#Boltzmann constant[erg/K]\n", "e=2.718 \n", "R=1.998 \t\t\t#Universal gas constant[cal/K]\n", "\t\n", "import math\n", "x=h*v/(k*T) \n", "a=R*x*e**-x/(1-e**-x) \t\t#a=E-Eo/T\n", "b=R*math.log(1-e**-x) \t\t#b=G-Eo/T\n", "S=a-b \t\t\t\t#[cal/deg]\n", "print\"The vibrational contribution to the entropy of F2 is\",round(S,4),\"cal/deg APPROX\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The vibrational contribution to the entropy of F2 is 0.1445 cal/deg APPROX\n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.16,Page number:211" ] }, { "cell_type": "code", "collapsed": false, "input": [ "T=1273 \t\t\t\t#Temperature[K]\n", "h=6.26*10**-27 \t\t\t#Planck's constant[J.s]\n", "k=1.381*10**-16 \t\t\t#Boltzmann constant[erg/K]\n", "T=1000 \t\t\t\t#Temperature[degrees]\n", "m=3.82*10**-23 \t\t\t#mass of Na [gm]\n", "I=(1.91*10**-23)*(3.078*10**-8)**2 \t#moment of inertia[gm.cm2]\n", "dE=0.73*1.602*10**-12 \t\t\t#[erg]\n", "v=159.23*(3*10**10)\t \t\t#frequency [s-1]\n", "R=82 \t\t\t\t\t#universal gas constant[cm3.atm/deg]\n", "u=2 \t\t\t\t\t#symmetry number\n", "L=6.023*10**23 \t\t\t\t#avogadro's number\n", "import math\n", "\t\n", "p=((3.14*m*k*T)**1.5)/h/h/h \n", "s=R*u*h*h/L/8/3.14/3.14/I/k \n", "q=1-(math.exp(-h*v/k/T)) \n", "r=math.exp(-dE/k/T) \n", "Kp=p*s*q*r \t\t\t\t#Equilibrium constant \n", "print\"The equilibrium constant is\",round(Kp,3) " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The equilibrium constant is 0.608\n" ] } ], "prompt_number": 13 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.17,Page number:212" ] }, { "cell_type": "code", "collapsed": false, "input": [ "T=298.0 #Temperature[K]\n", "m1=32.0 \n", "m2=36.0 \n", "m3=34.0 \n", "u1=8.0 \n", "u2=9.0 \n", "u3=16.0*18.0/34.0 \n", "z1=0.99924 \n", "z2=0.99951 \n", "z3=0.99940 \n", "h=6.26*10**-27 #Planck's constant[J.s]\n", "c=3.0*10**10 #Speed of light[m/s]\n", "k=1.38*10**-16 #Boltzman's constant[erg/K]\n", "vo1=1535.8 #vibration frequency of 16O18O [cm-1]\n", "vo2=1580.4 #vibration frequency of 16O2 [cm-1]\n", "vo3=1490.0 #vibration frequency of 18O2 [cm-1]\n", "dE=0.5*h*c*(2*vo1-vo2-vo3) #[erg]\n", "r=dE/k/T \n", "import math\n", "\n", "a=m3**3/m2**1.5/m1**1.5 \n", "b=(u3**2)*4/u2/u1 \n", "c=z3**2/z2/z1 \n", "Kp=a*b*c*math.exp(-r) \n", "print\"The value of equilibrium constant for isotopic exchange reaction is\",round(Kp,3) " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The value of equilibrium constant for isotopic exchange reaction is 3.996\n" ] } ], "prompt_number": 14 } ], "metadata": {} } ] }