{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 19:Electrochemistry" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example no:19.3,Page no:848" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable declaration\n", "E0cathode=0.8 #standard electrode potential of cathode(Ag+/Ag), V\n", "E0anode=-2.37 #standard electrode potential of anode(Mg2+/Mg), V\n", "\n", "#Calculation\n", "E0cell=E0cathode-E0anode #standard emf of the cell, V\n", "\n", "#Result\n", "print\"The standard emf of the cell is :\",E0cell,\"V\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The standard emf of the cell is : 3.17 V\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example no:19.4,Page no:850" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable declaration\n", "n=2.0 \n", "E0cathode=0.15 #standard electrode potential of cathode(Cu2+/Cu+), V\n", "E0anode=-0.14 #standard electrode potential of anode(Sn2+/Sn), V\n", "\n", "#Calculation\n", "E0cell=E0cathode-E0anode #standard emf of the cell, V\n", "import math\n", "K=math.exp(round(n*E0cell/0.0257,1)) #equilibrium constant, from the formula E0cell=0.0257*lnK/n\n", "\n", "#Result\n", "print\"The equilibrium constant for the given reaction is :%.e\"%K " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "0.29\n", "The equilibrium constant for the given reaction is :7e+09\n" ] } ], "prompt_number": 18 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example no:19.5,Page no:851" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable declaration\n", "n=6 \n", "F=96500 #faraday constant, J/V mol\n", "E0cathode=-2.87 #standard electrode potential of cathode(Ca2+/Ca), V\n", "E0anode=1.5 #standard electrode potential of anode(Au3+/Au), V\n", "\n", "#Calculation\n", "E0cell=E0cathode-E0anode #standard emf of the cell, V\n", "deltaG0=-n*F*E0cell #standard free energy change for the reaction, kJ/mol\n", "\n", "#Result\n", "print\"The standard free energy change for the reaction is :%.2e\"%(deltaG0/1000),\"kJ/mol\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The standard free energy change for the reaction is :2.53e+03 kJ/mol\n" ] } ], "prompt_number": 21 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example no:19.6,Page no:853" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable declaration\n", "n=2 \n", "F=96500 #faraday constant, J/V mol\n", "Co2=0.15 #conc of Co2+ ions, M\n", "Fe2=0.68 #conc of Fe2+ ions, M\n", "E0cathode=-0.44 #standard electrode potential of cathode(Fe2+/Fe), V\n", "E0anode=-0.28 #standard electrode potential of anode(Co2+/Co), V\n", "\n", "#Calculation\n", "import math\n", "E0cell=E0cathode-E0anode #standard emf of the cell, V\n", "Ecell=E0cell-0.0257/2*math.log(Co2/Fe2) #calculation of cell potential at non standard conditions, V\n", "\n", "#Result\n", "print \"E=\",round(Ecell,2),\"V\"\n", "if(Ecell>0):\n", " print\"The reaction would proceed spontaneously in the direction written\"\n", "else:\n", " print\"The reaction is not spontaneously in the direction written\"\n", " " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "E= -0.14 V\n", "The reaction is not spontaneously in the direction written\n" ] } ], "prompt_number": 23 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example no:19.7,Page no:855" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable declaration\n", "n=2 \n", "Zn=1 #conc of Zn2+ ions, M\n", "pH2=1 #pressure of H2 gas, atm\n", "Ecell=0.54 #emf of the cell, V\n", "E0cell=0.76 #standard emf of the cell, V\n", "\n", "#Calculation\n", "import math\n", "Q=math.exp(-(Ecell-E0cell)*2/0.0257) #since Ecell=E0cell-0.0257/2*log(Q) where Q=(Zn2+)*pH2/(H+)**2\n", "H=math.sqrt(Zn*pH2/Q) #the conc of H+ ions, M\n", "\n", "#Result\n", "print\"The molar concentration of H+ ion is :%.e\"%H,\"M\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The molar concentration of H+ ion is :2e-04 M\n" ] } ], "prompt_number": 24 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example no:19.9,Page no:870" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable declaration\n", "t=7.44*3600 #time, sec\n", "A=1.26 #current in ampere\n", "F=96500.0 #faraday constant, J/V mol\n", "R=0.0821 #gas constant, L atm/K\n", "T=273.0 #temperature in Kelvin\n", "P=1.0 #pressure in atm\n", "\n", "#Calculation\n", "q=A*t #charge passed, coulomb\n", "ne=q/F #moles of electrons\n", "nO2=ne/4.0 #moles of oxygen\n", "nH2=ne/2.0 #moles of H2\n", "VO2=nO2*R*T/P #volume of oxygen gas generated\n", "VH2=nH2*R*T/P #volume of H2 gas generated\n", "\n", "#Result\n", "print\"The volume of O2 gas is:\",round(VO2,2),\"L\"\n", "print\"Volume of H2 gas generated is:\",round(VH2,2),\"L\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The volume of O2 gas is: 1.96 L\n", "Volume of H2 gas generated is: 3.92 L\n" ] } ], "prompt_number": 26 } ], "metadata": {} } ] }