{ "metadata": { "name": "", "signature": "sha256:d1e925900cff60559a1ba3f62c2c267140215c90675c4dba42b1a473becca175" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "9: Molecular spectra" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 9.1, Page number 172" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "twoB=3.8626; #average spacing(per cm)\n", "h=6.626*10**-34; #planck's constant(Js)\n", "c=3*10**8; #speed of light(m/s)\n", "NA=6.022*10**23; #avagadro number(atoms/mole)\n", "mC=0.012; #isotopic mass of C(kg/mol)\n", "mO=0.016; #isotopic mass of O(kg/mol)\n", "\n", "#Calculation\n", "B=(twoB/2)*100; #average spacing(per m)\n", "I=h/(8*math.pi**2*B*c); \n", "mew=mC*mO/((mC+mO)*NA); #reduced mass(kg)\n", "r=math.sqrt(I/mew); #bond length(m)\n", "\n", "#Result\n", "print \"bond length is\",round(r*10**10,3),\"*10**-10 m\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "bond length is 1.128 *10**-10 m\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 9.2, Page number 173" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "T=300; #temperature(K)\n", "k=1.38*10**-23; #boltzmann constant(J/K)\n", "h=6.626*10**-34; #planck's constant(Js)\n", "c=3*10**8; #speed of light(m/s)\n", "lamda=10**-2; #wavelength(m)\n", "\n", "#Calculation\n", "E=3*k*T/2; #kinetic energy(J)\n", "deltaE=h*c/lamda; #energy seperation(J)\n", "\n", "#Result\n", "print \"kinetic energy is\",E,\"J\"\n", "print \"energy seperation is\",round(deltaE*10**23),\"*10**-23 J\"\n", "print \"deltaE is much smaller than E. hence substantial number of molecules will be there\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "kinetic energy is 6.21e-21 J\n", "energy seperation is 2.0 *10**-23 J\n", "deltaE is much smaller than E. hence substantial number of molecules will be there\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 9.3, Page number 175" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "ff=1876.06; #frequency of fundamental(per cm)\n", "fo=3724.2; #frequency of 1st overtone(per cm)\n", "\n", "#Calculation\n", "#ff=vebar*(1-(2*xe)) and fo=2*vebar*(1-(3*xe)). on solcing we get\n", "vebar=1903.98; #equilibrium vibration frequency(per cm)\n", "xe=7.33*10**-3; #anharmonicity constant\n", "E=vebar/2; #zero point energy(per cm)\n", "\n", "#Result\n", "print \"equilibrium vibration frequency is\",vebar,\"per cm\"\n", "print \"anharmonicity constant is\",round(xe*10**3,2),\"*10**-3\"\n", "print \"zero point energy is\",round(E),\"per cm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "equilibrium vibration frequency is 1903.98 per cm\n", "anharmonicity constant is 7.33 *10**-3\n", "zero point energy is 952.0 per cm\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 9.4, Page number 175" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "m=1.67*10**-27; #mass of proton(kg)\n", "m1=1.0087; #mass of 1H(u)\n", "m2=35.453; #mass of Cl(u)\n", "c=3*10**8; #velocity of light(m/sec)\n", "lamda0=3.465*10**-6; #wavelength(m)\n", "\n", "#Calculation\n", "mew=m*m1*m2/(m1+m2); #reduced mass(kg)\n", "k=4*math.pi**2*mew*(c/lamda0)**2; #force constant(N/m)\n", "\n", "#Result\n", "print \"force constant is\",round(k,1),\"N/m\"\n", "print \"answer varies due to rounding off errors\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "force constant is 484.7 N/m\n", "answer varies due to rounding off errors\n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 9.5, Page number 187" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "lamdae=4358.3*10**-8; #excited wavelength(cm)\n", "lamda=4768.5*10**-8; #wavelength(cm)\n", "\n", "#Calculation\n", "wne=1/lamdae; #wave number of exciting radiation(per cm)\n", "wn=1/lamda; #wave number of Raman line(per cm)\n", "new=wne-wn; #vibrational frequency(per cm)\n", "\n", "#Result\n", "print \"vibrational frequency is\",round(new),\"per cm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "vibrational frequency is 1974.0 per cm\n" ] } ], "prompt_number": 15 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 9.6, Page number 188" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "h=6.626*10**-34; #planck's constant(Js)\n", "c=3*10**8; #speed of light(m/s)\n", "sixB=346; #1st rotational Raman line(per cm)\n", "m1=1.673*10**-27; #mass of proton(kg)\n", "\n", "#Calculation\n", "m2=m1;\n", "B=(sixB/6)*100; #average spacing(per m)\n", "I=h/(8*math.pi**2*B*c); \n", "mew=m1*m2/(m1+m2); #reduced mass(kg)\n", "r=math.sqrt(I/mew); #bond length(m)\n", "\n", "#Result\n", "print \"bond length is\",round(r*10**10,3),\"*10**-10 m\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "bond length is 0.762 *10**-10 m\n" ] } ], "prompt_number": 18 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 9.7, Page number 193" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "gN=5.585; #value of gN\n", "h=6.626*10**-34; #planck's constant(Js)\n", "new=120*10**6; #frequency(Hz)\n", "mewn=5.0508*10**-27;\n", "\n", "#Calculation\n", "B0=h*new/(gN*mewn); #magnetic field strength(T)\n", "\n", "#Result\n", "print \"magnetic field strength is\",round(B0,3),\"T\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "magnetic field strength is 2.819 T\n" ] } ], "prompt_number": 20 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 9.8, Page number 194" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "gN=5.585; #value of gN\n", "h=6.626*10**-34; #planck's constant(Js)\n", "mewn=5.0508*10**-27;\n", "B0=1.65; #magnetic field(T)\n", "new=510*10**6; #frequency separation(Hz)\n", "\n", "#Calculation\n", "new0=gN*mewn*B0/h;\n", "delta=new/new0; #chemical shift(ppm)\n", "\n", "#Result\n", "print \"chemical shift is\",round(delta,2),\"ppm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "chemical shift is 7.26 ppm\n" ] } ], "prompt_number": 24 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 9.10, Page number 198" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "h=6.626*10**-34; #planck's constant(Js)\n", "new=35*10**9; #frequency(Hz)\n", "mewB=9.27*10**-24;\n", "B0=1.3; #magnetic field(T)\n", "\n", "#Calculation\n", "g=h*new/(mewB*B0); #electron g-factor\n", "\n", "#Result\n", "print \"electron g-factor is\",round(g,3)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "electron g-factor is 1.924\n" ] } ], "prompt_number": 26 } ], "metadata": {} } ] }