{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 20 - Statistical thermodynamics" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example I1 - Pg 477" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate the relative populations of boat and chair conformations\n", "#Initialization of variables\n", "import math\n", "E=22*1000. #kJ/mol\n", "T=293. #K \n", "#calculations\n", "ratio=math.pow(math.e,(-E/(8.31451*T)))\n", "#results\n", "print '%s %.1e' %(\"Relative populations of boat and chair conformations is \",ratio)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Relative populations of boat and chair conformations is 1.2e-04\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example I2 - Pg 478" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate the required ratio\n", "#Initialization of variables\n", "import math\n", "g2=5.\n", "g1=3.\n", "E2=6.\n", "E1=2.\n", "k=1.38*math.pow(10,-23) #J/K\n", "h=6.626*math.pow(10,-34) #J s\n", "B=3.18*math.pow(10,11) #Hz\n", "T =298 #K\n", "#calculations\n", "ratio=g2/g1 *(math.pow(math.e,((E1-E2)*h*B/(k*T))))\n", "#results\n", "print '%s %.2f' %(\"Ratio= \",ratio)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Ratio= 1.36\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example I3 - Pg 481" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate the translational partition function\n", "#Initialization of variables\n", "import math\n", "T=298 #K\n", "m=32*1.66054*math.pow(10,-27) #kg\n", "k=1.38066*math.pow(10,-23) #j/k\n", "V=math.pow(10,-4) #m^3\n", "h=6.62608*math.pow(10,-34) #J/s\n", "#calculations\n", "q=math.pow((2*math.pi*m*k*T),1.5) *V/h/h/h \n", "#results\n", "print '%s %.2e' %(\"Translational partition function = \",q)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Translational partition function = 1.75e+28\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example E1 - Pg 479" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate the partition function at 20 C\n", "#Initialization of variables\n", "import math\n", "E=22 #kJ/mol\n", "R=8.214 #J/K mol\n", "T=293 #K\n", "#Calculations\n", "q=1+math.pow(math.e,(-E*1000. /(R*T)))\n", "#results\n", "print '%s %.4f' %(\"At 20 C, partition function = \",q)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "At 20 C, partition function = 1.0001\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example E3 - Pg 485" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate the contribution to rotational motion\n", "#Initialization of variables\n", "import math\n", "k=1.38*math.pow(10,-23) #J/K\n", "h=6.626*math.pow(10,-34) #J s\n", "B=3.18*math.pow(10,11) #Hz\n", "T=298 #K\n", "R=8.314 #J/K mol\n", "#calculations\n", "Sm=R*(1+math.log(k*T/(h*B)))\n", "#results\n", "print '%s %.1f %s' %(\"Contribution to rotational motion=\",Sm,\"J/ K mol\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Contribution to rotational motion= 33.0 J/ K mol\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example E5 - Pg 488" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate the Equilibrium constant\n", "#Initialization of variables\n", "import math\n", "me=9.10939*math.pow(10,-31) #kg\n", "k=1.38*math.pow(10,-23) #J/K\n", "h=6.626*math.pow(10,-34) #J s\n", "p=math.pow(10,5) #Pa\n", "T=1000 #K\n", "R=8.314 #J/K mol\n", "I=376*1000. #J/mol\n", "#calculations\n", "K=math.pow((2*math.pi*me),1.5) *math.pow((k*T),2.5) /(p*h*h*h) *math.pow(math.e,(-I/(R*T)))\n", "#results\n", "print '%s %.2e' %(\"Equilibrium constant = \",K)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Equilibrium constant = 2.41e-19\n" ] } ], "prompt_number": 6 } ], "metadata": {} } ] }