{ "metadata": { "name": "", "signature": "sha256:299eac653f64d8a7c5614d61c55d5e5b51bd64ec7dc4bb7d26a6abfad893f9e1" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 9 : Gases and Vapour Mixtures" ] }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.1 Page no : 420" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variables\n", "V = 0.35; \t\t\t#m**3\n", "import math \n", "m_CO = 0.4; \t\t\t#kg\n", "m_air = 1; \t\t\t#kg\n", "m_O2 = 0.233; \t\t\t#kg\n", "m_N2 = 0.767; \t\t\t#kg\n", "T = 293.; \t\t\t#K\n", "R0 = 8.314; \t\t\t#kJ/kg K\n", "M_O2 = 32.; \t\t\t#Molecular mass of O2\n", "M_N2 = 28.; \t\t\t#Molecular mass of N2\n", "M_CO = 28.; \t\t\t#Molecular mass of CO\n", "\n", "# Calculations and Results\n", "\n", "p_O2 = m_O2*R0*10**3*T/M_O2/V/10**5; \t\t\t#bar\n", "print (\"partial pressure for p_O2 %.3f\")% (p_O2), (\"bar\")\n", "\n", "p_N2 = m_N2*R0*10**3*T/M_N2/V/10**5; \t\t\t#bar\n", "print (\"partial pressure for p_N2 %.3f\")% (p_N2), (\"bar\")\n", "\n", "p_CO = m_CO*R0*10**3*T/M_CO/V/10**5; \t\t\t#bar\n", "print (\"partial pressure for p_CO %.3f\")%(p_CO), (\"bar\")\n", "\n", "\n", "print (\"(ii) Total pressure in the vessel\")\n", "p = p_O2+p_N2+p_CO;\n", "print (\"p = %.3f\")% (p), (\"bar\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "partial pressure for p_O2 0.507 bar\n", "partial pressure for p_N2 1.907 bar\n", "partial pressure for p_CO 0.994 bar\n", "(ii) Total pressure in the vessel\n", "p = 3.408 bar\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.2 Page no : 421" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "# Variables\n", "R0 = 8.314;\n", "M_O2 = 32.;\n", "M_N2 = 28.;\n", "M_Ar = 40.;\n", "M_CO2 = 44.;\n", "\n", "# Calculations\n", "R_O2 = R0/M_O2; \t\t\t#kJ/kg K\n", "R_N2 = R0/M_N2; \t\t\t#kJ/kg K\n", "R_Ar = R0/M_Ar; \t\t\t#kJ/kg K\n", "R_CO2 = R0/M_CO2; \t\t\t#kJ/kg K\n", "\n", "O2 = 0.2314;\n", "N2 = 0.7553;\n", "Ar = 0.0128;\n", "CO2 = 0.0005;\n", "\n", "# Results\n", "print (\"(i) Gas constant for air\")\n", "R = O2*R_O2 + N2*R_N2 + Ar*R_Ar + CO2*R_CO2;\n", "print (\"R = %.3f\")%(R), (\"kJ/kg K\")\n", "\n", "print (\"(ii) Apparent molecular weight.\")\n", "M = R0/R;\n", "print (\"M = %.3f\")%(M)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(i) Gas constant for air\n", "R = 0.287 kJ/kg K\n", "(ii) Apparent molecular weight.\n", "M = 28.954\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.3 Page no : 422" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "# Variables\n", "p = 1.; \t\t\t#bar\n", "#For oxygen\n", "m_O2 = 0.2314;\n", "M_O2 = 32;\n", "n_O2 = m_O2/M_O2;\n", "#For Nitrogen\n", "m_N2 = 0.7553;\n", "M_N2 = 28.;\n", "n_N2 = m_N2/M_N2;\n", "#For Argon\n", "m_Ar = 0.0128;\n", "M_Ar = 40;\n", "n_Ar = m_Ar/M_Ar;\n", "\n", "#For CO2\n", "m_CO2 = 0.0005;\n", "M_CO2 = 44;\n", "n_CO2 = m_CO2/M_CO2;\n", "\n", "# Calculations and Results\n", "n = n_O2 + n_N2 + n_Ar + n_CO2;\n", "\n", "#Let Vi/V be A\n", "A_O2 = n_O2/n * 100;\n", "print (\"Vi/V of O2 = %.3f\")%(A_O2),(\"%\")\n", "\n", "A_N2 = n_N2/n * 100;\n", "print (\"Vi/V of N2 = %.3f\")%(A_N2), (\"%\")\n", "\n", "A_Ar = n_Ar/n *100;\n", "print (\"Vi/V of Ar %.3f\")% (A_Ar), (\"%\")\n", "\n", "A_CO2 = n_CO2/n * 100;\n", "print (\"Vi/V of CO2 = %.3f\")% (A_CO2), (\"%\")\n", "\n", "\n", "P_O2 = n_O2/n*p;\n", "print (\"Partial pressure of O2 = %.3f\")% (P_O2), (\"bar\")\n", "\n", "P_N2 = n_N2/n*p;\n", "print (\"Partial pressure of N2 = %.3f\")% (P_N2), (\"bar\")\n", "\n", "P_Ar = n_Ar/n*p;\n", "print (\"Partial pressure of Ar = %.3f\")% (P_Ar), (\"bar\")\n", "\n", "P_CO2 = n_CO2/n*p;\n", "print (\"Partial pressure of CO2 = %.4f\")% (P_CO2), (\"bar\")\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Vi/V of O2 = 20.937 %\n", "Vi/V of N2 = 78.103 %\n", "Vi/V of Ar 0.927 %\n", "Vi/V of CO2 = 0.033 %\n", "Partial pressure of O2 = 0.209 bar\n", "Partial pressure of N2 = 0.781 bar\n", "Partial pressure of Ar = 0.009 bar\n", "Partial pressure of CO2 = 0.0003 bar\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.4 Page no : 423" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "# Variables\n", "p = 1.*10**5; \t\t\t#Pa\n", "T = 293.; \t\t\t#K\n", "n_CO2 = 1.; \t\t\t#moles of CO2\n", "n = 4.; \t\t\t#moles of air\n", "M_CO2 = 44.;\n", "M_N2 = 28.;\n", "M_O2 = 32.;\n", "\n", "#Let A be the volumeetric analysis\n", "A_O2 = 0.21;\n", "A_N2 = 0.79;\n", "\n", "# Calculations and Results\n", "n_O2 = A_O2*n;\n", "n_N2 = A_N2*n;\n", "\n", "print (\"(i) The masses of CO2, O2 and N2, and the total mass\")\n", "\n", "m_CO2 = n_CO2*M_CO2;\n", "print (\"Mass of CO2 = %.3f\")%(m_CO2),(\"kg\")\n", "\n", "m_O2 = n_O2*M_O2;\n", "print (\"Mass of O2 = %.3f\")%(m_O2),(\"kg\")\n", "\n", "m_N2 = n_N2*M_N2;\n", "print (\"Mass of N2 = %.3f\")%(m_N2),(\"kg\")\n", "\n", "m = m_CO2 + m_O2 + m_N2;\n", "print (\"Total mass = %.3f\")% (m), (\"kg\")\n", "\n", "\n", "print (\"(ii) The percentage carbon content by mass\")\n", "#Since the molecular weight of carbon is 12, therefore, there are 12 kg of carbon present for every mole of CO2\n", "m_C = 12; \t\t\t#kg\n", "\n", "C = m_C/m*100;\n", "print (\"Percentage carbon in mixture %.3f\")%(C),(\"%\")\n", "\n", "\n", "print (\"(iii) The apparent molecular weight and the gas consmath.tant for the mixture\")\n", "n = n_CO2 + n_O2 + n_N2;\n", "M = n_CO2/n*M_CO2 + n_O2/n*M_O2 + n_N2/n*M_N2;\n", "print (\"Apparent Molecular weight %.3f\")%(M)\n", "\n", "R0 = 8.314;\n", "R = R0/M;\n", "print (\"Gas constant for the mixture = %.3f\")%(R),(\"kJ/kg K\")\n", "\n", "\n", "print (\"(iv) The specific volume of the mixture\")\n", "v = R*10**3*T/p;\n", "print (\"specific volume = %.3f\")%(v),(\"m**3/kg\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(i) The masses of CO2, O2 and N2, and the total mass\n", "Mass of CO2 = 44.000 kg\n", "Mass of O2 = 26.880 kg\n", "Mass of N2 = 88.480 kg\n", "Total mass = 159.360 kg\n", "(ii) The percentage carbon content by mass\n", "Percentage carbon in mixture 7.530 %\n", "(iii) The apparent molecular weight and the gas consmath.tant for the mixture\n", "Apparent Molecular weight 31.872\n", "Gas constant for the mixture = 0.261 kJ/kg K\n", "(iv) The specific volume of the mixture\n", "specific volume = 0.764 m**3/kg\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.5 Page no : 424" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variables\n", "p = 1.*10**5; \t\t\t#Pa\n", "T = 298.; \t\t\t#K\n", "M_H2 = 2.;\n", "M_O2 = 32.;\n", "R0 = 8314.;\n", "# ratio = V_H2/V_O2 = 2;\n", "ratio = 2;\n", "\n", "# Calculations and Results\n", "print (\"(i) The mass of O2 required\")\n", "\t\t\t#Let the mass of O2 per kg of H2 = x kg\n", "m_H2 = 1; \t\t\t#kg\n", "n_H2 = m_H2/M_H2;\n", "\n", "# n_O2 = x/M_O2\n", "x = M_O2*n_H2/ratio;\n", "print (\"Mass of O2 per kg of H2 = %.3f\")%(x), (\"kg\")\n", "\n", "print (\"(ii) The volume of the container\")\n", "n_O2 = x/M_O2;\n", "n = n_H2 + n_O2;\n", "V = n*R0*T/p;\n", "print (\"V = %.3f\")%(V), (\"m**3\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(i) The mass of O2 required\n", "Mass of O2 per kg of H2 = 8.000 kg\n", "(ii) The volume of the container\n", "V = 18.582 m**3\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.6 Page no : 424" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "#Let composition of mixture by volume be denoted by c1\n", "#Let Final composition desired be denoted by c2\n", "\n", "# Variables\n", "c1_H2 = 0.78;\n", "c1_CO = 0.22;\n", "c2_H2 = 0.52;\n", "c2_CO = 0.48;\n", "M_H2 = 2.;\n", "M_CO = 28.;\n", "\n", "# Calculations\n", "M = c1_H2*M_H2 + c1_CO*M_CO;\n", "# Let x kg of mixture be removed and y kg of CO be added.\n", "x = (c1_H2 - c2_H2)/c1_H2*M;\n", "\n", "# Results\n", "print (\"Mass of mixture removed = %.3f\")%(x), (\"kg\")\n", "\n", "y = M_CO/M*x;\n", "print (\"Mass of CO added = %.3f\")%(y),(\"kg\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Mass of mixture removed = 2.573 kg\n", "Mass of CO added = 9.333 kg\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.7 Page no : 425" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "import math \n", "\n", "# Variables\n", "ratio = 1./8; \t\t\t#volume ratio; v1/v2\n", "T1 = 1223.; \t\t\t#K\n", "cp_CO2 = 1.235; \t\t\t#kJ/kg K\n", "cp_O2 = 1.088; \t\t\t#kJ/kg K\n", "cp_N2 = 1.172; \t\t\t#kJ/kg K\n", "n_CO2 = 0.13;\n", "n_O2 = 0.125;\n", "n_N2 = 0.745;\n", "M_CO2 = 44.;\n", "M_O2 = 32.;\n", "M_N2 = 28.;\n", "\n", "\n", "# Calculations\n", "m_CO2 = M_CO2*n_CO2;\n", "m_O2 = M_O2*n_O2;\n", "m_N2 = M_N2*n_N2;\n", "m = m_CO2 + m_O2 + m_N2;\n", "\n", "# Let Fraction by mass be denoted by F\n", "F_CO2 = m_CO2/m;\n", "F_O2 = m_O2/m;\n", "F_N2 = m_N2/m;\n", "cp = F_CO2*cp_CO2 + F_O2*cp_O2 + F_N2*cp_N2;\n", "R0 = 8.314;\n", "R = F_CO2*R0/M_CO2 + F_O2*R0/M_O2 + F_N2*R0/M_N2;\n", "\n", "cv = cp - R;\n", "n = 1.2;\n", "\n", "print (\"(i) The workdone\")\n", "T2 = T1*(ratio)**(n-1);\n", "W = R*(T1-T2)/(n-1);\n", "print (\"W = %.3f\")%(W), (\"kJ/kg\")\n", "\n", "print (\"(ii) The heat flow\")\n", "du = cv*(T2-T1);\n", "Q = du + W;\n", "print (\"Q = %.3f\")%(Q), (\"kJ/kg\")\n", "\n", "\n", "print (\"(iii) Change of entropy per kg of mixture\")\n", "ds_1A = R*math.log(1/ratio); \t\t\t#isothermal process\n", "ds_2A = cv*math.log(T1/T2);\n", "\n", "ds_12 = ds_1A - ds_2A;\n", "print (\"change of entropy = %.3f\")% (ds_12), (\"kJ/kg K\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(i) The workdone\n", "W = 565.669 kJ/kg\n", "(ii) The heat flow\n", "Q = 190.777 kJ/kg\n", "(iii) Change of entropy per kg of mixture\n", "change of entropy = 0.191 kJ/kg K\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.8 Page no : 427" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\n", "# Variables\n", "M_CO2 = 44.;\n", "M_H2 = 2.;\n", "M_N2 = 28.;\n", "M_CH4 = 16.;\n", "M_CO = 28.;\n", "\n", "# Let volumetric analysis be denoted by V\n", "V_CO = 0.28;\n", "V_H2 = 0.13;\n", "V_CH4 = 0.04;\n", "V_CO2 = 0.04;\n", "V_N2 = 0.51;\n", "Cp_CO = 29.27; \t\t\t#kJ/mole K\n", "Cp_H2 = 28.89; \t\t\t#kJ/mole K\n", "Cp_CH4 = 35.8; \t\t\t#kJ/mole K\n", "Cp_CO2 = 37.22; \t\t\t#kJ/mole K\n", "Cp_N2 = 29.14; \t\t\t#kJ/mole K\n", "R0 = 8.314; \n", "\n", "# Calculations and Results\n", "Cp = V_CO*Cp_CO + V_H2*Cp_H2 + V_CO2*Cp_CO2 + V_CH4*Cp_CH4 + V_N2*Cp_N2;\n", "print (\"Cp = %.3f\")%(Cp), (\"kJ/mole K\")\n", "\n", "Cv = Cp-R0;\n", "print (\"Cv = %.3f\")% (Cv), (\"kJ/mole K\")\n", "\n", "M = V_CO*M_CO + V_H2*M_H2 + V_CO2*M_CO2 + V_CH4*M_CH4 + V_N2*M_N2;\n", "\n", "cp = Cp/M;\n", "print (\"cp = %.3f\")%(cp), (\"kJ/kg K\")\n", "\n", "cv = Cv/M;\n", "print (\"cv %.3f\")% (cv), (\"kJ/kg K\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Cp = 29.733 kJ/mole K\n", "Cv = 21.419 kJ/mole K\n", "cp = 1.200 kJ/kg K\n", "cv 0.864 kJ/kg K\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.9 Page no : 427" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\n", "# Variables\n", "p = 1.3 \t\t\t#bar\n", "R0 = 8.314;\n", "M_CO2 = 44.;\n", "M_O2 = 32.;\n", "M_N2 = 28.;\n", "M_CO = 28.;\n", "m_O2 = 0.1;\n", "m_N2 = 0.7;\n", "m_CO2 = 0.15;\n", "m_CO = 0.05;\n", "#Considering 1 kg of mixture\n", "m = 1; \t\t\t#kg\n", "\n", "# Calculations\n", "#let moles be denoted by n\n", "n_O2 = m_O2/M_O2;\n", "n_N2 = m_N2/M_N2;\n", "n_CO2 = m_CO2/M_CO2;\n", "n_CO = m_CO/M_CO;\n", "M = 1/(m_O2/M_O2 + m_N2/M_N2 + m_CO2/M_CO2 + m_CO/M_CO);\n", "n = m/M;\n", "x_O2 = n_O2/n;\n", "x_N2 = n_N2/n;\n", "x_CO2 = n_CO2/n;\n", "x_CO = n_CO/n;\n", "\n", "# Results\n", "print (\"(i) Partial pressures of the constituents\")\n", "P_O2 = x_O2*p;\n", "print (\"Partial pressure of O2 = %.3f\")% (P_O2), (\"bar\")\n", "\n", "P_N2 = x_N2*p;\n", "print (\"Partial pressure of N2 = %.3f\")% (P_N2), (\"bar\")\n", "\n", "P_CO2 = x_CO2*p;\n", "print (\"Partial pressure of CO2 = %.3f\")% (P_CO2), (\"bar\")\n", "\n", "P_CO = x_CO*p;\n", "print (\"Partial pressure of CO = %.3f\")% (P_CO), (\"bar\")\n", "\n", "R_mix = R0/M;\n", "print (\"Gas constant of mixture = %.3f\")%(R_mix), (\"kJ/kg K\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(i) Partial pressures of the constituents\n", "Partial pressure of O2 = 0.122 bar\n", "Partial pressure of N2 = 0.975 bar\n", "Partial pressure of CO2 = 0.133 bar\n", "Partial pressure of CO = 0.070 bar\n", "Gas constant of mixture = 0.277 kJ/kg K\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.10 Page no : 428" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variables\n", "p = 4.*10**5; \t\t \t#Pa\n", "import math \n", "T = 293.; \t\t\t #K\n", "R0 = 8.314;\n", "\n", "m_N2 = 4.; \t \t\t #kg\n", "m_CO2 = 6.; \t\t\t #kg\n", "\n", "M_N2 = 28.; \t\t \t #Molecular mass\n", "M_CO2 = 44.; \t\t\t #Molecular mass\n", "\n", "n_N2 = m_N2/M_N2; \t\t\t#moles of N2\n", "n_CO2 = m_CO2/M_CO2; \t\t\t#moles of CO2\n", "\n", "x_N2 = n_N2/(n_N2+n_CO2);\n", "print (\"x_N2 = %.3f\")% (x_N2)\n", "\n", "x_CO2 = n_CO2/(n_CO2+n_N2);\n", "print (\"x_CO2 = %.3f\")% (x_CO2)\n", "\n", "\n", "print (\"(ii) The equivalent molecular weight of the mixture\")\n", "M = x_N2*M_N2 + x_CO2*M_CO2;\n", "print (\"M = %.3f\")%(M), (\"kg/kg-mole\")\n", "\n", "print (\"(iii) The equivalent gas consmath.tant of the mixture\")\n", "m = m_N2+m_CO2;\n", "Rmix = (m_N2*(R0/M_N2) + m_CO2*(R0/M_CO2))/m;\n", "print (\"Rmix = %.3f\")% (Rmix), (\"kJ/kg K\")\n", "\n", "print (\"(iv) The partial pressures and partial volumes\")\n", "P_N2 = x_N2*p/10**5;\n", "print (\"P_N2 = %.3f\")% (P_N2), (\"bar\")\n", "\n", "P_CO2 = x_CO2*p/10**5;\n", "print (\"P_CO2 = %.3f\")% (P_CO2), (\"bar\")\n", "\n", "V_N2 = m_N2*R0/M_N2*T/p*10**3;\n", "print (\"V_N2 %.3f\")% (V_N2), (\"m**3\")\n", "\n", "V_CO2 = m_CO2*R0/M_CO2*T/p*10**3;\n", "print (\"V_CO2 %.3f\")% (V_CO2), (\"m**3\")\n", "\n", "print (\"(v) The volume and density of the mixture\")\n", "\n", "V = m*Rmix*10**3*T/p;\n", "print (\"V = %.3f\")% (V), (\"m**3\")\n", "\n", "rho_mix = m/V;\n", "print (\"Density of mixture = %.3f\")% (rho_mix), (\"kg/m**3\")\n", "\n", "\n", "print (\"(vi) cp and cv of the mixture\")\n", "\n", "y_N2 = 1.4;\n", "cv_N2 = (R0/M_N2)/(y_N2 - 1);\n", "cp_N2 = cv_N2*y_N2;\n", "\n", "y_CO2 = 1.286;\n", "cv_CO2 = (R0/M_CO2)/(y_CO2 - 1);\n", "cp_CO2 = cv_CO2*y_CO2;\n", "\n", "cp = (m_N2*cp_N2 + m_CO2*cp_CO2)/(m_N2+m_CO2);\n", "print (\"cp = %.3f\")%(cp),(\"kJ/kg K\")\n", "\n", "cv = (m_N2*cv_N2 + m_CO2*cv_CO2)/(m_N2+m_CO2);\n", "print (\"cv = %.3f\")%(cv),(\"kJ/kg K\")\n", "\n", "T1 = 293.; \t\t\t#K\n", "T2 = 323.; \t\t\t#K\n", "dU = m*cv*(T2-T1);\n", "print (\"Change in internal energy = %.3f\")% (dU), (\"kJ\")\n", "\n", "dH = m*cp*(T2-T1);\n", "print (\"Change in enthalpy = %.3f\")% (dH), (\"kJ\")\n", "\n", "dS = m*cv*math.log(T2/T1); \t\t\t#Consmath.tant volume process\n", "print (\"Change in entropy = %.3f\")% (dS), (\"kJ/kg K\")\n", "\n", "\n", "print (\"When the mixture is heated at constant pressure\")\n", "\n", "print (\"If the mixture is heated at constant pressure \u0394U and \u0394H will remain the same\")\n", "\n", "dS = m*cp*math.log(T2/T1);\n", "print (\"Change in entropy = %.3f\")% (dS), (\"kJ/kg K\")\n", "\n", "\n", "# Note : Answers are slightly different because of rounding error." ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "x_N2 = 0.512\n", "x_CO2 = 0.488\n", "(ii) The equivalent molecular weight of the mixture\n", "M = 35.814 kg/kg-mole\n", "(iii) The equivalent gas consmath.tant of the mixture\n", "Rmix = 0.232 kJ/kg K\n", "(iv) The partial pressures and partial volumes\n", "P_N2 = 2.047 bar\n", "P_CO2 = 1.953 bar\n", "V_N2 0.870 m**3\n", "V_CO2 0.830 m**3\n", "(v) The volume and density of the mixture\n", "V = 1.700 m**3\n", "Density of mixture = 5.881 kg/m**3\n", "(vi) cp and cv of the mixture\n", "cp = 0.925 kJ/kg K\n", "cv = 0.693 kJ/kg K\n", "Change in internal energy = 208.001 kJ\n", "Change in enthalpy = 277.644 kJ\n", "Change in entropy = 0.676 kJ/kg K\n", "When the mixture is heated at constant pressure\n", "If the mixture is heated at constant pressure \u0394U and \u0394H will remain the same\n", "Change in entropy = 0.902 kJ/kg K\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.11 Page no : 430" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "# Variables\n", "Cv_O2 = 21.07; \t\t\t#kJ/mole K\n", "Cv_CO = 20.86; \t\t\t#kJ/mole K\n", "p_O2 = 8*10**5; \t\t\t#Pa\n", "p_CO = 1*10**5; \t\t\t#Pa\n", "V_O2 = 1.8; \t\t\t#m**3\n", "V_CO = 3.6; \t\t\t#m**3\n", "T_O2 = 323.; \t\t\t#K\n", "T_CO = 293.; \t\t\t#K\n", "R0 = 8314.;\n", "\n", "# Calculations and Results\n", "n_O2 = p_O2*V_O2/R0/T_O2;\n", "n_CO = p_CO*V_CO/R0/T_CO;\n", "n = (n_O2+n_CO);\n", "V = (V_O2+V_CO);\n", "\n", "print (\"(i) Final temperature (T) and pressure (p) of the mixture\")\n", "\n", "#Before mixing\n", "U1 = n_O2*Cv_O2*T_O2 + n_CO*Cv_CO*T_CO;\n", "\n", "T = U1/(n_O2*Cv_O2 + n_CO*Cv_CO);\n", "t = T-273;\n", "\n", "print (\"Final temperature = %.3f\")% (t), (\"\u00b0C\")\n", "\n", "p = n*R0*T/V/10**5;\n", "print (\"Final pressure = %.3f\")% (p), (\"bar\")\n", "\n", "\n", "#For oxygen\n", "dS_O1A = n_O2*R0*math.log(V/V_O2); \t\t\t#isothermal process\n", "dS_O2A = n_O2*Cv_O2*math.log(T_O2/T); \t\t\t#consmath.tant volume process\n", "dS_O12 = dS_O1A - dS_O2A; \t\t\t# Change of entropy of O2\n", "\n", "#For CO\n", "dS_CO12 = n_CO*R0*math.log(V/V_CO) + n_CO*Cv_CO*math.log(T/T_CO); \t\t\t#Change of entropy of CO\n", "dS = (dS_O12 + dS_CO12)/10**3;\n", "print (\"(ii)Change of entropy of system = %.3f\")% (dS), (\"kJ/K\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(i) Final temperature (T) and pressure (p) of the mixture\n", "Final temperature = 43.569 \u00b0C\n", "Final pressure = 3.334 bar\n", "(ii)Change of entropy of system = 5.396 kJ/K\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.12 Page no : 432" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "import math \n", "\n", "# Variables\n", "p_A = 16.*10**5; \t\t\t#Pa\n", "p_B = 6.4*10**5; \t\t\t#Pa\n", "\n", "T_A = 328.; \t\t\t#K\n", "T_B = 298.; \t\t\t#K\n", "\n", "n_A = 0.6 \t\t\t#kg-mole\n", "m_B = 3; \t \t\t#kg\n", "\n", "R0 = 8314.;\n", "M_A = 28.; \n", "y = 1.4;\n", "\n", "V_A = n_A*R0*T_A/p_A;\n", "m_A = n_A*M_A;\n", "R = R0/M_A;\n", "V_B = m_B*R*T_B/p_B;\n", "V = V_A+V_B;\n", "m = m_A+m_B;\n", "T = 303.; \t\t\t#K\n", "\n", "print (\"(a) (i) Final equilibrium pressure, p\")\n", "p = m*R*T/V/10**5;\n", "print (\"p = %.3f\")% (p), (\"bar\")\n", "\n", "cv = R/10**3/(y-1);\n", "\n", "print (\"(ii) Amount of heat transferred, Q :\")\n", "\n", "U1 = cv*(m_A*T_A + m_B*T_B);\n", "U2 = m*cv*T;\n", "Q = U2-U1;\n", "print (\"Q = %.3f\")% (Q),(\"kJ\")\n", "\n", "print (\"(b) If the vessel were insulated :\")\n", "\n", "print (\"(i) Final temperature,\")\n", "\n", "T = cv*(m_A*T_A + m_B*T_B)/(m*cv);\n", "t = T-273;\n", "print (\"T = %.3f\")% (t), (\"\u00b0C\")\n", "\n", "\n", "print (\"(ii) Final pressure\")\n", "\n", "p = m*R*T/V/10**5;\n", "print (\"p = %.3f\")% (p), (\"bar\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(a) (i) Final equilibrium pressure, p\n", "p = 12.393 bar\n", "(ii) Amount of heat transferred, Q :\n", "Q = -300.640 kJ\n", "(b) If the vessel were insulated :\n", "(i) Final temperature,\n", "T = 50.455 \u00b0C\n", "(ii) Final pressure\n", "p = 13.230 bar\n" ] } ], "prompt_number": 13 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.13 Page no : 434" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "import math \n", "\n", "# Variables\n", "m_O2 = 3.; \t\t\t#kg\n", "M_O2 = 32.;\n", "m_N2 = 9.; \t\t\t#kg\n", "M_N2 = 28.;\n", "R0 = 8.314;\n", "\n", "# Calculations\n", "R_O2 = R0/M_O2;\n", "R_N2 = R0/M_N2;\n", "x_O2 = (m_O2/M_O2)/((m_O2/M_O2) + (m_N2/M_N2));\n", "x_N2 = (m_N2/M_N2)/((m_O2/M_O2) + (m_N2/M_N2));\n", "dS = -m_O2*R_O2*math.log(x_O2) -m_N2*R_N2*math.log(x_N2);\n", "\n", "# Results\n", "print (\"Change in entropy = %.3f\")% (dS),(\"kJ/kg K\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Change in entropy = 1.844 kJ/kg K\n" ] } ], "prompt_number": 14 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.14 Page no : 434" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variables\n", "m_N2 = 2.5; \t\t\t#kg \n", "M_N2 = 28.;\n", "p_N2 = 15.; \t\t\t#bar\n", "p_total = 20.; \t\t\t#bar\n", "\n", "# Calculations\n", "n_N2 = m_N2/M_N2;\n", "p_O2 = p_total-p_N2;\n", "n_O2 = p_O2/p_N2*n_N2;\n", "M_O2 = 32;\n", "m_O2 = n_O2*M_O2;\n", "\n", "# Results\n", "print (\"Mass of O2 added = %.3f\")% (m_O2), (\"kg\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Mass of O2 added = 0.952 kg\n" ] } ], "prompt_number": 15 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.15 Page no : 435" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "# Variables\n", "n_O2 = 1.;\n", "M_N2 = 28.;\n", "M_O2 = 32.;\n", "\n", "# Calculations and Results\n", "print (\"(i) Moles of N2 per mole of O2 :\")\n", "n_N2 = n_O2*0.79/0.21;\n", "print (\"n_N2 = %.3f\")%(n_N2),(\"moles\")\n", "\n", "n = n_O2+n_N2;\n", "print (\"(ii)\")\n", "p = 1; \t\t\t#atm\n", "\n", "p_O2 = n_O2/n*p;\n", "print (\"p_O2 = %.3f\")% (p_O2), (\"atm\")\n", "\n", "p_N2 = n_N2/n*p;\n", "print (\"p_N2 = %.3f\")% (p_N2), (\"atm\")\n", "\n", "\n", "x = n_N2*M_N2/(n_N2*M_N2+n_O2*M_O2);\n", "print (\"(iii) The kg of nitrogen per kg of mixture = %.3f\")% (x), (\"kg N2/kg mix\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(i) Moles of N2 per mole of O2 :\n", "n_N2 = 3.762 moles\n", "(ii)\n", "p_O2 = 0.210 atm\n", "p_N2 = 0.790 atm\n", "(iii) The kg of nitrogen per kg of mixture = 0.767 kg N2/kg mix\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.16 Page no : 436" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "import math \n", "\n", "# Variables\n", "V = 0.6; \t\t\t#m**3\n", "p1 = 12.*10**5; \t\t\t#Pa\n", "p2 = 18.*10**5; \t\t\t#Pa\n", "T = 298.; \t\t\t#K\n", "R0 = 8.314;\n", "x_O2 = 0.23;\n", "x_N2 = 0.77;\n", "\n", "n = p1*V/R0/10**3/T;\n", "#Considering 100 kg of air\n", "m_O2 = 23.; \t\t\t#kg\n", "m_N2 = 77.; \t\t\t#kg\n", "M_O2 = 32.;\n", "M_N2 = 28.;\n", "m = 100.; \t\t\t#kg\n", "\n", "# Calculations and Results\n", "R = (m_O2/M_O2 + m_N2/M_N2)*R0/m; \t\t\t#for air\n", "M = R0/R \t \t\t#for air\n", "\n", "m = p1*V/R/T/10**3;\n", "\n", "m_O2 = x_O2*m;\n", "print (\"Mass of O2 = %.3f\")% (m_O2), (\"kg\")\n", "\n", "m_N2 = x_N2*m;\n", "print (\"Mass of N2 = %.3f\")% (m_N2), (\"kg\")\n", "\n", "#After adding CO2 in the vessel\n", "p2 = 18.*10**5; \t\t\t#Pa;\n", "\n", "p_CO2 = 6.*10**5; \t\t\t#Pa\n", "M_CO2 = 44.;\n", "R_CO2 = R0/M_CO2;\n", "\n", "m_CO2 = p_CO2*V/(R_CO2*10**3*T);\n", "print (\"Mass of CO2 = %.3f\")% (m_CO2), (\"kg\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Mass of O2 = 1.927 kg\n", "Mass of N2 = 6.451 kg\n", "Mass of CO2 = 6.393 kg\n" ] } ], "prompt_number": 18 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.17 Page no : 437" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variables\n", "V = 6; \t\t \t#m**3\n", "A = 0.45; \n", "B = 0.55;\n", "R_A = 0.288; \t\t\t#kJ/kg K\n", "R_B = 0.295; \t\t\t#kJ/kg K\n", "m = 2. \t\t\t#kg\n", "T = 303. \t\t\t #K\n", "\n", "# Calculations\n", "print (\"(i) The partial pressures\")\n", "m_A = A*m;\n", "m_B = B*m;\n", "\n", "p_A = m_A*R_A*10**3*T/V/10**5; \t\t\t#bar\n", "print (\"p_A = %.3f\")% (p_A), (\"bar\")\n", "\n", "p_B = m_B*R_B*10**3*T/V/10**5; \t\t\t#bar\n", "print (\"p_B = %.3f\")% (p_B), (\"bar\")\n", "\n", "\n", "print (\"(ii) The total pressure\")\n", "p = p_A+p_B;\n", "print (\"p = %.3f\")% (p), (\"bar\")\n", "\n", "\n", "print (\"(iii) The mean value of R for the mixture\")\n", "Rm = (m_A*R_A + m_B*R_B)/(m_A + m_B);\n", "print (\"Rm = %.3f\")% (Rm), (\"kJ/kg K\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(i) The partial pressures\n", "p_A = 0.131 bar\n", "p_B = 0.164 bar\n", "(ii) The total pressure\n", "p = 0.295 bar\n", "(iii) The mean value of R for the mixture\n", "Rm = 0.292 kJ/kg K\n" ] } ], "prompt_number": 19 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.18 Page no : 438" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "# Variables\n", "m_O2 = 4.; \t\t\t#kg\n", "m_N2 = 6.; \t\t\t#kg\n", "p = 4.*10**5; \t\t\t#Pa\n", "T = 300.; \t\t\t#K\n", "M_O2 = 32.;\n", "M_N2 = 28.;\n", "m = 10.; \t\t\t#kg\n", "\n", "# Calculations and Results\n", "print (\"(i) The mole fraction of each component\")\n", "n_O2 = m_O2/M_O2;\n", "n_N2 = m_N2/M_N2;\n", "\n", "x_O2 = n_O2/(n_O2+n_N2);\n", "print (\"x_O2 = %.3f\")% (x_O2)\n", "\n", "x_N2 = n_N2/(n_N2+n_O2);\n", "print (\"x_N2 = %.3f\")% (x_N2)\n", "\n", "\n", "print (\"(ii) The average molecular weight\")\n", "M = (n_O2*M_O2 + n_N2*M_N2)/(n_O2 + n_N2);\n", "print (\"M = %.3f\")%(M)\n", "\n", "print (\"(iii) The specific gas consmath.tant\")\n", "R0 = 8.314;\n", "R = R0/M;\n", "print (\"R = %.3f\")% (R), (\"kJ/kg K\")\n", "\n", "print (\"(iv) The volume and density\")\n", "V = m*R*T*10**3/p;\n", "print (\"V = %.3f\")%(V), (\"m**3\")\n", "\n", "rho = (m_O2/V) + (m_N2/V);\n", "print (\"density = %.3f\")% (rho), (\"kg/m**3\")\n", "\n", "\n", "print (\"(v) The partial pressures and partial volumes\")\n", "p_O2 = n_O2*R0*10**3*T/V/10**5; \t\t\t#bar\n", "print (\"p_O2 = %.3f\")%(p_O2), (\"bar\")\n", "\n", "p_N2 = n_N2*R0*10**3*T/V/10**5; \t\t\t#bar\n", "print (\"p_N2 = %.3f\")% (p_N2), (\"bar\")\n", "\n", "V_O2 = x_O2*V;\n", "print (\"V_O2 = %.3f\")% (V_O2), (\"m**3\")\n", "\n", "V_N2 = x_N2*V;\n", "print (\"V_N2 = %.3f\")% (V_N2), (\"m**3\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(i) The mole fraction of each component\n", "x_O2 = 0.368\n", "x_N2 = 0.632\n", "(ii) The average molecular weight\n", "M = 29.474\n", "(iii) The specific gas consmath.tant\n", "R = 0.282 kJ/kg K\n", "(iv) The volume and density\n", "V = 2.116 m**3\n", "density = 4.727 kg/m**3\n", "(v) The partial pressures and partial volumes\n", "p_O2 = 1.474 bar\n", "p_N2 = 2.526 bar\n", "V_O2 = 0.779 m**3\n", "V_N2 = 1.336 m**3\n" ] } ], "prompt_number": 20 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.19 Page no : 439" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "import math \n", "\n", "# Variables\n", "cp_CO2 = 0.85; \t\t\t#kJ/kg K\n", "cp_N2 = 1.04; \t\t\t#kJ/kg K\n", "m_CO2 = 4.; \t\t\t#kg\n", "T1_CO2 = 313.; \t\t\t#K\n", "m_N2 = 8.; \t\t\t#kg\n", "T1_N2 = 433.; \t\t\t#K\n", "p2 = 0.7; \t\t\t#bar\n", "p1_CO2 = 1.4; \t\t\t#bar\n", "p1_N2 = 1.;\n", "R = 8.314;\n", "M_CO2 = 44.;\n", "M_N2 = 28.;\n", "R_CO2 = R/M_CO2;\n", "R_N2 = R/M_N2;\n", "\n", "# Calculations and Results\n", "print (\"(i) Final temperature, T2\")\n", "T2 = (m_CO2*cp_CO2*T1_CO2 + m_N2*cp_N2*T1_N2)/(m_CO2*cp_CO2 + m_N2*cp_N2);\n", "print (\"T2 = %.3f\")%(T2),(\"K\")\n", "\n", "print (\"(ii) Change in entropy\")\n", "n_CO2 = 0.0909;\n", "n_N2 = 0.2857;\n", "n = n_CO2 + n_N2;\n", "x_CO2 = n_CO2/n;\n", "x_N2 = n_N2/n;\n", "p2_CO2 = x_CO2*p2;\n", "p2_N2 = x_N2*p2;\n", "\n", "dS = m_CO2*cp_CO2*math.log(T2/T1_CO2) - m_CO2*R_CO2*math.log(p2_CO2/p1_CO2) + m_N2*cp_N2*math.log(T2/T1_N2) - m_N2*R_N2*math.log(p2_N2/p1_N2);\n", "print (\"dS = %.3f\")%(dS), (\"kJ/K\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(i) Final temperature, T2\n", "T2 = 398.188 K\n", "(ii) Change in entropy\n", "dS = 3.223 kJ/K\n" ] } ], "prompt_number": 21 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.20 Page no : 440" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\n", "# Variables\n", "cv_O2 = 0.39; \t\t\t#kJ/kg K\n", "cv_N2 = 0.446; \t\t\t#kJ/kg K\n", "n_O2 = 1.;\n", "n_N2 = 2.;\n", "M_O2 = 32.;\n", "M_N2 = 28.;\n", "m_O2 = 32.; \t\t\t#kg\n", "m_N2 = 2*28.; \t\t\t#kg\n", "T_O2 = 293.; \t\t\t#K\n", "T_N2 = 301.; \t\t\t#K\n", "R0 = 8.314;\n", "\n", "# Calculations\n", "p_O2 = 2.5*10**5; \t\t\t#Pa\n", "p_N2 = 1.5*10**5; \t\t\t#Pa\n", "T2 = (m_O2*cv_O2*T_O2 + m_N2*cv_N2*T_N2)/(m_O2*cv_O2 + m_N2*cv_N2);\n", "V_O2 = n_O2*R0*10**5*T_O2/p_O2;\n", "V_N2 = n_N2*R0*10**5*T_N2/p_N2;\n", "V = V_O2+V_N2;\n", "dS = m_O2*(cv_O2*math.log(T2/T_O2) + R0/M_O2*math.log(V/V_O2)) + m_N2*(cv_N2*math.log(T2/T_N2) + R0/M_N2*math.log(V/V_N2));\n", "\n", "# Results\n", "print (\"Entropy change in the mixing process = %.3f\")%(dS),(\"kJ\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Entropy change in the mixing process = 16.627 kJ\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.21 Page no : 421" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "import math \n", "\n", "# Variables\n", "cv_N2 = 0.744; \t\t\t#kJ/kg K\n", "cv_H2 = 10.352; \t\t\t#kJ/kg K\n", "cp_N2 = 1.041; \t\t\t#kJ/kg K\n", "cp_H2 = 14.476; \t\t\t#kJ/kg K\n", "V = 0.45; \t\t\t#m**3\n", "V_H2 = 0.3; \t\t\t#m**3\n", "V_N2 = 0.15; \t\t\t#m**3\n", "p_H2 = 3.*10**5; \t\t\t#Pa\n", "p_N2 = 6.*10**5; \t\t\t#Pa\n", "T_H2 = 403.; \t\t\t#K\n", "T_N2 = 303.; \t\t\t#K\n", "\n", "# Calculations and Results\n", "R_H2 = 8.314/2;\n", "R_N2 = 8.314/28;\n", "\n", "print (\"(i) Temperature of equilibrium mixture\")\n", "\n", "m_H2 = p_H2*V_H2/(R_H2*10**3)/T_H2;\n", "m_N2 = p_N2*V_N2/(R_N2*10**3)/T_N2;\n", "T2 = (m_H2*cv_H2*T_H2 + m_N2*cv_N2*T_N2)/(m_H2*cv_H2 + m_N2*cv_N2);\n", "print (\"T2 = %.3f\")%(T2),(\"K\")\n", "\n", "print (\"(ii) Pressure of the mixture\")\n", "p2_H2 = m_H2*R_H2*10**3*T2/V;\n", "p2_N2 = m_N2*R_N2*10**3*T2/V;\n", "\n", "p2 = p2_H2+p2_N2;\n", "print (\"p2 = %.3f\")%(p2/10**5),(\"bar\")\n", "\n", "print (\"(iii) Change in entropy :\")\n", "\n", "dS_H2 = m_H2*(cp_H2*math.log(T2/T_H2) - R_H2*math.log(p2_H2/p_H2));\n", "print (\"Change in entropy of H2 = %.3f\")%(dS_H2),(\"kJ/K\")\n", "\n", "dS_N2 = m_N2*(cp_N2*math.log(T2/T_N2) - R_N2*math.log(p2_N2/p_N2));\n", "print (\"Change in entropy of N2 = %.3f\")%(dS_N2),(\"kJ/K\")\n", "\n", "dS = dS_H2+dS_N2;\n", "\n", "print (\"Total change in entropy = %.3f\")%(dS),(\"kJ/K\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(i) Temperature of equilibrium mixture\n", "T2 = 345.767 K\n", "(ii) Pressure of the mixture\n", "p2 = 3.998 bar\n", "(iii) Change in entropy :\n", "Change in entropy of H2 = 0.006 kJ/K\n", "Change in entropy of N2 = 0.425 kJ/K\n", "Total change in entropy = 0.430 kJ/K\n" ] } ], "prompt_number": 23 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 9.22 Page no : 443" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "import math \n", "\n", "# Variables\n", "cv_N2 = 0.745; \t\t\t#kJ/kg K\n", "cv_CO2 = 0.653; \t\t#kJ/kg K\n", "cp_N2 = 1.041; \t\t\t#kJ/kg K\n", "cp_CO2 = 0.842; \t\t#kJ/kg K\n", "m_N2 = 4.; \t\t\t#kg\n", "m_CO2 = 6.; \t\t#kg\n", "pmix = 4.; \t\t \t#bar\n", "m = m_N2+m_CO2;\n", "\n", "T1 = 298.; \t\t\t #K\n", "T2 = 323.; \t\t\t #K\n", "\n", "# Calculations and Results\n", "cv_mix = (m_N2*cv_N2 + m_CO2*cv_CO2)/(m_N2+m_CO2);\n", "print (\"cv_mix = %.3f\")% (cv_mix), (\"kJ/kg K\")\n", "\n", "cp_mix = (m_N2*cp_N2 + m_CO2*cp_CO2)/(m_N2+m_CO2);\n", "print (\"cp_mix = %.3f\")% (cp_mix), (\"kJ/kg K\")\n", "\n", "dU = m*cv_mix*(T2-T1);\n", "print (\"Change in internal energy = %.3f\")% (dU), (\"kJ\")\n", "\n", "dH = m*cp_mix*(T2-T1);\n", "print (\"Change in enthalpy = %.3f\")% (dH), (\"kJ\")\n", "\n", "dS = m_N2*cv_N2*math.log(T2/T1) + m_CO2*cv_CO2*math.log(T2/T1);\n", "print (\"Change in entropy = %.3f\")% (dS), (\"kJ/K\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "cv_mix = 0.690 kJ/kg K\n", "cp_mix = 0.922 kJ/kg K\n", "Change in internal energy = 172.450 kJ\n", "Change in enthalpy = 230.400 kJ\n", "Change in entropy = 0.556 kJ/K\n" ] } ], "prompt_number": 24 } ], "metadata": {} } ] }