{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 4 - Heat effects" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example: 4.1 Page: 118" ] }, { "cell_type": "code", "execution_count": 2, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Example: 4.1 - Page: 118\n", "\n", "\n", "Value of Qv is -326.40 kcal\n", "\n" ] } ], "source": [ "from __future__ import division\n", "print \"Example: 4.1 - Page: 118\\n\\n\"\n", "\n", "# Solution\n", "\n", "#*****Data*****#\n", "Qp = -327## [kcal]\n", "T = 27 + 273## [K]\n", "R = 2*10**(-3)## [kcal/K mol]\n", "#*************#\n", "\n", "# The reaction involved is:\n", "# C2H5OH(l) + 3O2(g) = 2CO2(g) + 3H2O(l)\n", "deltan = 2 - 3#\n", "Qv = Qp - deltan*R*T## [kcal]\n", "print \"Value of Qv is %.2f kcal\\n\"%(Qv)#" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example: 4.2 Page: 119" ] }, { "cell_type": "code", "execution_count": 3, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Example: 4.2 - Page: 119\n", "\n", "\n", "Heat produced in the reaction is -1019.9 kcal\n", "\n" ] } ], "source": [ "from __future__ import division\n", "print \"Example: 4.2 - Page: 119\\n\\n\"\n", "\n", "# Solution\n", "\n", "#*****Data*****#\n", "# Mg + (1/2)O2 = MgO ...............(1)\n", "deltaH1 = -610.01## [kcal]\n", "# 2Fe + (3/2)O2 = Fe2O3 ............(2)\n", "deltaH2 = -810.14## [kcal]\n", "#*************#\n", "\n", "# 3Mg + Fe2O3 = 3MgO + 2Fe .........(3)\n", "# Multiplying (1) by 3 and substracting from (2), we get (3):\n", "deltaH = 3*deltaH1 - deltaH2## [kcal]\n", "print \"Heat produced in the reaction is %.1f kcal\\n\"%(deltaH)#" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example: 4.3 Page: 121" ] }, { "cell_type": "code", "execution_count": 4, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Example: 4.3 - Page: 121\n", "\n", "\n", "The standard heat of formation of methane is -74.75 kJ/gmol\n", "\n" ] } ], "source": [ "from __future__ import division\n", "print \"Example: 4.3 - Page: 121\\n\\n\"\n", "\n", "# Solution\n", "\n", "#*****Data*****#\n", "# 2H2(g) + O2(g) ---------------> 2H2O .....................(1)\n", "deltaH1 = -241.8*2## [kJ/gmol H2]\n", "# C(graphite) + O2(g) =---------> CO2(g) ...................(2)\n", "deltaH2 = -393.51## [kJ/gmol C]\n", "# CH4(g) + 2O2(g) ---------------> CO2(g) + 2H2O(l) ........(3)\n", "deltaH3 = -802.36## [kJ/mol CH4]\n", "#*************#\n", "\n", "# For standard heat of formation of methane, (a) + (b) - (c)\n", "# C + 2H2 ------------------------> CH4\n", "deltaHf = deltaH1 + deltaH2 - deltaH3## [kJ/gmol]\n", "print \"The standard heat of formation of methane is %.2f kJ/gmol\\n\"%(deltaHf)#" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example: 4.4 Page: 122" ] }, { "cell_type": "code", "execution_count": 5, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Example: 4.4 - Page: 122\n", "\n", "\n", "Energy supplied by reaction A is -69.2 kJ\n", "\n", "Energy supplied by reaction B is -2802.8 kJ\n", "\n", "Reaction B supplies more energy to the organism\n", "\n" ] } ], "source": [ "from __future__ import division\n", "print \"Example: 4.4 - Page: 122\\n\\n\"\n", "\n", "# Solution\n", "\n", "#*****Data*****#\n", "deltaH_C6H12O6 = -1273## [kcal]\n", "deltaH_C2H5OH = -277.6## [kcal]\n", "deltaH_CO2 = -393.5## [kcal]\n", "deltaH_H2O = -285.8## [kcal]\n", "#**************#\n", "\n", "# C6H12O6(s) = 2C2H5OH(l) + 2CO2(g) ..........................(A)\n", "deltaH_A = 2*deltaH_C2H5OH + 2*deltaH_CO2 - deltaH_C6H12O6## [kJ]\n", "# C6H12O6(s) + 6O2(g) = 6CO2(g) + 6H2O(l) ...................(B)\n", "deltaH_B = 6*deltaH_CO2 + 6*deltaH_H2O - deltaH_C6H12O6## [kJ]\n", "print \"Energy supplied by reaction A is %.1f kJ\\n\"%(deltaH_A)#\n", "print \"Energy supplied by reaction B is %.1f kJ\\n\"%(deltaH_B)#\n", "if deltaH_A < deltaH_B:\n", " print \"Reaction A supplies more energy to the organism\\n\"\n", "else:\n", " print \"Reaction B supplies more energy to the organism\\n\"\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example: 4.5 Page: 122" ] }, { "cell_type": "code", "execution_count": 6, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Example: 4.5 - Page: 122\n", "\n", "\n", "Heat of formation of ZnSO4 is -233.48 kcal/kmol\n", "\n" ] } ], "source": [ "from __future__ import division\n", "print \"Example: 4.5 - Page: 122\\n\\n\"\n", "\n", "# Solution\n", "\n", "#*****Data*****#\n", "# Zn + S = ZnS ....................................................(A)\n", "deltaH_A = -44## [kcal/kmol]\n", "# ZnS + 3O2 = 2ZnO + 2SO2 .........................................(B)\n", "deltaH_B = -221.88## [kcal/kmol]\n", "# 2SO2 + O2 = 2SO3 ................................................(C)\n", "deltaH_C = -46.88## [kcal/kmol]\n", "# ZnO + SO3 = ZnSO4 ...............................................(D)\n", "deltaH_D = -55.10## [kcal/kmol]\n", "#***************#\n", "\n", "# Multiplying (A) by 2 & (D) by (2) and adding (A), (B), (C) & (D)\n", "# Zn + S + 2O2 = ZnSO4\n", "deltaH = 2*deltaH_A + deltaH_B + deltaH_C + 2*deltaH_D## [kcal/kmol for 2 kmol of ZnSO4]\n", "print \"Heat of formation of ZnSO4 is %.2f kcal/kmol\\n\"%(deltaH/2)#" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example: 4.6 Page: 124" ] }, { "cell_type": "code", "execution_count": 7, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Example: 4.6 - Page: 124\n", "\n", "\n", "Standard Heat of formation of NH3 is -11.8 kcal\n" ] } ], "source": [ "from __future__ import division\n", "print \"Example: 4.6 - Page: 124\\n\\n\"\n", "\n", "# Solution\n", "\n", "#*****Data*****#\n", "# HC : Heat of Combustion\n", "HC_NH3 = -90.6## [kcal]\n", "HC_H2 = -68.3## [kcal]\n", "#*************#\n", "\n", "# Heat of combustion of NH3:\n", "# 2NH3 + 3O = N2 + 3H2O ............................ (A)\n", "# Heat of combustion of H2:\n", "# H2 + O = H2O ..................................... (B)\n", "# Multiplying (B) by 3 & substracting from (A), we get:\n", "# 2NH3 = N2 + 3H2 .................................. (C)\n", "# Hf : Heat of Formation\n", "Hf_NH3 = -(2*HC_NH3 - 3*HC_H2)/2## [kcal]\n", "print \"Standard Heat of formation of NH3 is %.1f kcal\"%(Hf_NH3)#" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example: 4.7 Page: 125" ] }, { "cell_type": "code", "execution_count": 8, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Example: 4.7 - Page: 125\n", "\n", "\n", "The maximum attainable temperature is 2566.2 K\n" ] } ], "source": [ "from __future__ import division\n", "from scipy.optimize import fsolve\n", "print \"Example: 4.7 - Page: 125\\n\\n\"\n", "\n", "# Solution\n", "\n", "#*****Data*****#\n", "# HC : Heat of Combustion\n", "HC_C2H2 = -310600# # [cal]\n", "#**************#\n", "\n", "# C2H2 + (5/2)O2 = 2CO2 + H2O\n", "Q = -HC_C2H2## [cal]\n", "# The gases present in the flame zone after combustion are carbon dioxide, water vapor and the unreacted nitrogen of the air.\n", "# Since (5/2) mole of oxygen were required for combustion, nitrogen required would be 10 mol.\n", "# Hence the composition of the resultant gas would be 2 mol CO2, 1 ol H2 & 10 mol N2.\n", "# Q = integrate('Cp(T)','T',T,298)#\n", "# On integrating we get:\n", "# Q = 84.52*(T - 298) + 18.3*10**(-3)*(T**2 - 298**2)\n", "#deff('[y] = f(T)','y = Q - 84.52*(T - 298) - 18.3*10**(-3)*(T**2 - 298**2)')#\n", "def f(T):\n", " y = Q - 84.52*(T - 298) - 18.3*10**(-3)*(T**2 - 298**2)\n", " return y\n", "\n", "T = fsolve(f,7)## [K]\n", "print \"The maximum attainable temperature is %.1f K\"%(T)#" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example: 4.8 Page: 126" ] }, { "cell_type": "code", "execution_count": 9, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Example: 4.8 - Page: 126\n", "\n", "\n", "The theoretical temperature of combustion is 1906 degree Celsius\n" ] } ], "source": [ "print \"Example: 4.8 - Page: 126\\n\\n\"\n", "\n", "# Solution\n", "\n", "#*****Data*****#\n", "Cp_CO2 = 54.56## [kJ/mol K]\n", "Cp_O2 = 35.20## [kJ/mol K]\n", "Cp_steam = 43.38## [kJ/mol K]\n", "Cp_N2 = 33.32## [kJ/mol K]\n", "# 2C2H6(g) + 7O2(g) = 4CO2(g) + 6H2O(g)\n", "deltaH_273 = -1560000## [kJ/kmol]\n", "#************#\n", "\n", "# Since the air is 25% in excess of the amount required,the combustion may be written as:\n", "# C2H6(g) + (7/2)O2(g) = 2CO2(g) + 3H2O(g)\n", "# 25% excess air is supplied.\n", "# Since the air contains N2 = 79% and O2 = 21%\n", "# C2H6(g) + 3.5O2(g) + 0.25*3.5O2(g) + (4.375*(79/21))N2 = 2CO2 + 3H2O + 0.875O2 + 16.46N2 .................. (A)\n", "# Considering the reaction (A),\n", "# Amount of O2:\n", "O2 = 3.5 + 3.5*0.25## [mol]\n", "# Amount of N2 required:\n", "N2 = 4.375*(79/21)## [mol]\n", "# Let the initial temperature of ethane and air be 0 OC and the temperature of products of combustion be T OC\n", "# Since heat librated by combustion = heat accumulated by combustion products\n", "Q = -deltaH_273## [kJ/mol K]\n", "T = Q/(2*Cp_CO2 + 3*Cp_steam + 0.875*Cp_O2 + N2*Cp_N2)## [OC]\n", "print \"The theoretical temperature of combustion is %d degree Celsius\"%(T)#" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example: 4.9 Page: 129" ] }, { "cell_type": "code", "execution_count": 10, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Example: 4.9 - Page: 129\n", "\n", "\n", "Laten heat of ice at -20 OC is 1266 cal/mol\n", "\n" ] } ], "source": [ "from __future__ import division\n", "print \"Example: 4.9 - Page: 129\\n\\n\"\n", "\n", "# Solution\n", "\n", "#*****Data*****#\n", "T1 = 273## [K]\n", "T2 = 253## [K]\n", "deltaH_273 = 1440## [cal/mol]\n", "Cp = 8.7## [cal/mol]\n", "#**************#\n", "\n", "deltaH_253 = deltaH_273 + Cp*(T2 - T1)## [cal/mol]\n", "print \"Laten heat of ice at -20 OC is %d cal/mol\\n\"%(deltaH_253)#" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example: 4.10 Page: 129" ] }, { "cell_type": "code", "execution_count": 11, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Example: 4.10 - Page: 129\n", "\n", "\n", "Heat of formation at 1273 K is -11172 cal\n" ] } ], "source": [ "from __future__ import division\n", "print \"Example: 4.10 - Page: 129\\n\\n\"\n", "\n", "# Solution\n", "\n", "#*****Data*****#\n", "T2 = 1273## [K]\n", "T1 = 300## [K]\n", "deltaH_300 = -11030## [cal/mol]\n", "#*************#\n", "\n", "# The chemical reaction involved is:\n", "# N2 + 3H2 = 2NH3\n", "# (1/2)N2 + (3/2)H2 = NH3\n", "# deltaH_1273 = deltaH_300 + integrate('Cp_NH3(T) - (1/2)*Cp_N2(T) - (1/2)*Cp_H2(T)','T',1273,300)#\n", "from sympy.mpmath import quad\n", "deltaH_1273 = deltaH_300 + quad(lambda T:(6.2 + 7.8*10**(-3)*T - 7.2*10**(-6)*T**2) - (1/2)*(6.45 + 1.4*10**(-3)*T) - (1/2)*(6.94 - 0.2*10**(-3)*T),[1273,300])## [cal]\n", "print \"Heat of formation at 1273 K is %d cal\"%(deltaH_1273)#" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example: 4.11 Page: 130" ] }, { "cell_type": "code", "execution_count": 12, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Example: 4.11 - Page: 130\n", "\n", "\n", "Percent of excess air supplied is 39.9 %\n" ] } ], "source": [ "from __future__ import division\n", "print \"Example: 4.11 - Page: 130\\n\\n\"\n", "\n", "# Solution\n", "\n", "#*****Data*****#\n", "CO2 = 13.4## [percent by volume]\n", "N2 = 80.5## [percent by volume]\n", "O2 = 6.1## [percent by volume]\n", "#*************#\n", "\n", "# Basis : 100 cubic m of flue gas.\n", "Vol_N2_flue = N2## [Volume of Nitrogen in flue gas, cubic m]\n", "Vol_O2_flue = O2## [Volume of O2 in flue gas, cubic m]\n", "Vol_Air = N2/0.79## [Volume of air supplied, cubic m]\n", "Vol_O2 = Vol_Air*0.21## [Volume of O2 in air supply, cubic m]\n", "Vol_O2_cumbustion = Vol_O2 - Vol_O2_flue## [Volume of O2 used up in cumbustion of the fuel, cubic m]\n", "Excess_Air = Vol_O2_flue/Vol_O2_cumbustion * 100## [percent of excess air supplied]\n", "print \"Percent of excess air supplied is %.1f %%\"%(Excess_Air)#" ] } ], "metadata": { "kernelspec": { "display_name": "Python 2", "language": "python", "name": "python2" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 2 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython2", "version": "2.7.9" } }, "nbformat": 4, "nbformat_minor": 0 }