{ "metadata": { "name": "", "signature": "sha256:aba24805b98ee0919f2ef39d5927b5007d2ce98264adcd2e65263a9fbffd1f67" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 15:CHEMICAL EQUILIBRIUM" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.1, Page No:676" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable declaration\n", "# (b).Number of moles of each constituents\n", "nCH4=2; # Number of moles of CH4\n", "\n", "#Calculation\n", "E=3-nCH4; # Amount of reaction from (a) and refer example 15.1 (a)\n", "nH2O=1-E;# Number of moles of H2O\n", "nCO=1+E;# Number of moles of CO\n", "nH2=4+3*E;# Number of moles of H2\n", "\n", "#Results\n", "print \"(b).Number of moles of each constituents\",\"\\nNumber of moles of H2O = \",nH2O\n", "print \"Number of moles of CO = \",nCO,\"\\nNumber of moles of H2 = \",nH2" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(b).Number of moles of each constituents \n", "Number of moles of H2O = 0\n", "Number of moles of CO = 2 \n", "Number of moles of H2 = 7\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.2, Page No:680" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Variable declaration\n", "T0=298; # Given temperature in kelvin\n", "R_1=8.314; # Universal gas constant in kJ/kg mol K\n", "# (a).CO+1/2 O2 = CO2\n", "# From table of properties of combustion\n", "del_hfco2=-393509;# Enthalpy of heat \n", "del_hfco=-110525;# Enthalpy of heat \n", "s_co2=213.795;# Entropy of heat \n", "s_co=197.652;# Entropy of heat \n", "s_o2=205.142;# Entropy of heat \n", "\n", "#Calculation for (a)\n", "del_Ga=(del_hfco2-del_hfco-T0*(s_co2-s_co-(1/2*s_o2)));\n", "Ka=math.exp (abs (del_Ga)/(R_1*1000*T0));\n", "\n", "#Result for (a)\n", "print \"(a).CO+1/2 O2 = CO2\"\n", "print (\" The equilibrium constant at 298 K = %0.3f (Error in textbook) \")%Ka\n", "\n", "#Calculation for (b)\n", "# (b).2CO + O2 = 2CO2\n", "Kb=math.exp (2*abs (del_Ga)/(R_1*1000*T0));\n", "\n", "#Result for (b)\n", "print \"\\n(b).2CO + O2 = 2CO2\"\n", "print (\"The equilibrium constant at 298 K = %0.3f (Error in textbook)\")%Kb\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(a).CO+1/2 O2 = CO2\n", " The equilibrium constant at 298 K = 1.123 (Error in textbook) \n", "\n", "(b).2CO + O2 = 2CO2\n", "The equilibrium constant at 298 K = 1.262 (Error in textbook)\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.3, Page No:686" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "T0=298; # Temperature of surroundings in kelvin\n", "R_1=8.314; # Universal gas constant in kJ/kg mol K\n", "T=2800; # Given Temperature in kelvin\n", "\n", "#Calculation\n", "# From table of properties of combustion\n", "del_hfco2=-393509; # Enthalpy of heat \n", "del_hfco=-110525; # Enthalpy of heat \n", "del_H=del_hfco2-del_hfco; # Standard enthalpy of reaction\n", "Ka=1.202*10**45; # The equilibrium constant From the example 15.2\n", "K1=math.log (Ka);\n", "K=math.exp(-(del_H/R_1)*((1/T)-(1/T0))+K1);\n", "\n", "#Result\n", "print\"K =\",round(K,3),\" (roundoff error)\"\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "K = 5.687 (roundoff error)\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.5, Page No:689" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Variable declaration\n", "T=2800; # Temperature of combustion in kelvin\n", "p=1; # Pressure of combustion in atm\n", "# For this reverse reaction at 2800K and 1atm, from Table 15.1\n", "K=44.168; # K=e^3.788;\n", "\n", "#Calculation\n", "K=math.sqrt (K); # For stoichiometric equation CO+1/2 O2 = CO2 which is halved\n", "# From equation 15.24a and by the iteration process we get the following\n", "a=0.198;\n", "b=(1+a)/2;\n", "c=1-a;\n", "\n", "#Results\n", "print \"The balance for the actual reaction equation CO + O2 \u2192 aCO + bO2 + cCO2 is given by \"\n", "print \"a =\",a,\"\\nb =\",b,\"\\nc =\",c\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The balance for the actual reaction equation CO + O2 \u2192 aCO + bO2 + cCO2 is given by \n", "a = 0.198 \n", "b = 0.599 \n", "c = 0.802\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.6, Page No:691" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "# By driving the equation for equilibrium constant as shown in example 15.6 we get 6.646(6)^(1/6)=((1-a)/a)((3+a)/(1+a))^1/2\n", "# by simple iteration process we get\n", "a=0.095;\n", "\n", "#Calculations\n", "b=(1+a)/2;\n", "c=1-a;\n", "\n", "#Results\n", "print \"The equilibrium composition of CO = \",a,\"mol (roundoff error)\"\n", "print \"The equilibrium composition of O2 = \",b,\"mol (roundoff error)\"\n", "print \"The equilibrium composition of CO2 = \",c,\"mol (roundoff error)\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The equilibrium composition of CO = 0.095 mol (roundoff error)\n", "The equilibrium composition of O2 = 0.5475 mol (roundoff error)\n", "The equilibrium composition of CO2 = 0.905 mol (roundoff error)\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.7, Page NO:691" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Variable declaration\n", "T=2800; # Temperature of combustion in kelvin\n", "p=1; # Pressure of combustion in atm\n", "# For this reverse reaction at 2800K and 1atm, from Table 15.1\n", "K=44.168; # K=e^3.788;\n", "\n", "#Calculations\n", "K=math.sqrt (K); # For stoichiometric equation CO+1/2 O2 = CO2 which is halved\n", "# From equation 15.24a and by the iteration process we get the following\n", "a=0.302;\n", "b=(1+a)/2;\n", "c=1-a;\n", "\n", "#Results\n", "print \"The balance for the actual reaction equation CO + 1/2O2 + 1.88N2 \u2194 aCO + bO2 + cCO2 +3.76N2 is given by \"\n", "print \"a =\",a,\"\\nb =\",b,\"\\nc =\",c" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The balance for the actual reaction equation CO + 1/2O2 + 1.88N2 \u2194 aCO + bO2 + cCO2 +3.76N2 is given by \n", "a = 0.302 \n", "b = 0.651 \n", "c = 0.698\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.8, Page No:693" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Variable declaration\n", "T=3000; # Temperature of combustion in kelvin\n", "p=1; # Pressure of combustion in atm\n", "T0=298; # Temperature of surroundings in kelvin\n", "R_1=8.314; # Universal gas constant in kJ/kg mol K\n", "# Gibbs functions at 298K from Table 14.1\n", "del_gNO=86550; # In kJ/kmol\n", "del_gNO2=51310; # In kJ/kmol\n", "# From table of properties of combustion\n", "del_hfNO=90250; # Enthalpy of heat \n", "del_hfNO2=33180; # Enthalpy of heat \n", "\n", "#Calculations\n", "K1=math.exp (-(del_hfNO/R_1)*((1/T)-(1/T0))-((del_gNO)/(R_1*T0)));\n", "K2=math.exp (-(del_hfNO2/R_1)*((1/T)-(1/T0))-((del_gNO2)/(R_1*T0)));\n", "# By solving equilibrium equations by iteration method\n", "E1=0.228; E2=0.0007;\n", "yNO=E1/4.76; # Mole fraction of NO in exhaust gas\n", "yNO2=E2/4.76; # Mole fraction of NO2 in exhaust gas\n", "\n", "#Results\n", "print \"Percentage of NOx present in the exhaust gas \",\"\\nMole fraction of NO in exhaust gas = \",round(yNO*100,2),\"%\"\n", "print \"Mole fraction of NO2 in exhaust gas = \",round(yNO2*100,4),\"%\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Percentage of NOx present in the exhaust gas \n", "Mole fraction of NO in exhaust gas = 4.79 %\n", "Mole fraction of NO2 in exhaust gas = 0.0147 %\n" ] } ], "prompt_number": 7 } ], "metadata": {} } ] }