{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 5: Chemical Kinetics and Catalysis" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem: 1, Page no: 149" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Variables\n", "K = 3.5 * 10 ** - 2 # Rate constant\n", "\n", "# Solution\n", "print \"First order reaction = 0.693 / K\"\n", "t_05 = 0.693 / K\n", "print \"Time taken for half the initial concentration to react\", t_05, \"minutes\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "First order reaction = 0.693 / K\n", "Time taken for half the initial concentration to react 19.8 minutes\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem: 2, Page no: 150" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Variables\n", "t05 = 40 # minutes\n", "\n", "# Solution\n", "print \"Rate constant = 0.693 / t05\"\n", "K = 0.693 / t05\n", "print \"Rate constant\", \"{:.4f}\".format(K), \"/ min\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Rate constant = 0.693 / t05\n", "Rate constant 0.0173 / min\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem: 3, Page no: 150" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import log10\n", "\n", "# Variables\n", "t0 = 37.0 # cm^3 of KMnO4\n", "t5 = 29.8 # cm^3 of KMnO4\n", "t15 = 19.6 # cm^3 of KMnO4\n", "t25 = 12.3 # cm^3 of KMnO4\n", "t45 = 5.00 # cm^3 of KMnO4\n", "\n", "# Solution\n", "K5 = 2.303 / 5 * log10(t0 / t5)\n", "K15 = 2.303 / 15 * log10(t0 / t15)\n", "K25 = 2.303 / 25 * log10(t0 / t25)\n", "K45 = 2.303 / 45 * log10(t0 / t45)\n", "\n", "print \"At t = 5 min, K =\", \"{:.3e}\".format(K5), \"/min\"\n", "print \"At t = 15 min, K =\", \"{:.3e}\".format(K15), \"/min\"\n", "print \"At t = 25 min, K =\", \"{:.3e}\".format(K25), \"/min\"\n", "print \"At t = 45 min, K =\", \"{:.3e}\".format(K45), \"/min\"\n", "print \"As the different values of K are nearly same, so the reaction\",\n", "print \"is of first-order\"\n", "K = (K45 + K25 + K5 + K15) / 4\n", "print \"The average value of K = \", \"{:.3e}\".format(K), \"/min\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "At t = 5 min, K = 4.329e-02 /min\n", "At t = 15 min, K = 4.237e-02 /min\n", "At t = 25 min, K = 4.406e-02 /min\n", "At t = 45 min, K = 4.449e-02 /min\n", "As the different values of K are nearly same, so the reaction is of first-order\n", "The average value of K = 4.355e-02 /min\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem : 4, Page no: 150" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Variables\n", "t = 60 # min\n", "x = \"0.5a\"\n", "K = 5.2 * 10 ** - 3 # / mol L / min\n", "\n", "# Solution\n", "a = 1 / (t * K)\n", "print \"Initial concentration\", \"{:.3f}\".format(a), \"mol / L\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Initial concentration 3.205 mol / L\n" ] } ], "prompt_number": 13 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem: 5, Page no: 151" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import log10\n", "\n", "# Solution\n", "print \"99.9 % / 50 % =\",\n", "times = round((2.303 * log10(100 / (100 - 99.9))) / (2.303 * log10(100 / (100 - 50))))\n", "print times\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "99.9 % / 50 % = 10.0\n" ] } ], "prompt_number": 18 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem: 6, Page no: 151" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import log10\n", "\n", "# Constants\n", "R = 1.987 # cal / K / mol\n", "\n", "# Variables\n", "T1 = 273.0 # K\n", "T2 = 303.0 # K\n", "K1 = 2.45 * 10 ** -5\n", "K2 = 162 * 10 ** -5\n", "\n", "# Solution\n", "Ea = log10(K2 / K1) * R * 2.303 / ((T2 - T1) / (T1 * T2))\n", "print \"The activation energy of the reaction is\", int(Ea), \"cal / mol\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The activation energy of the reaction is 22968 cal / mol\n" ] } ], "prompt_number": 22 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem: 7, Page no: 151" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Variables\n", "t05 = 30 # minutes\n", "a = 0.1 # M\n", "\n", "# Solution\n", "print \"For second order reaction,\"\n", "print \"t0.5 = 1 / Ka\"\n", "K = 1 / (a * t05)\n", "print \"The rate constant is\", \"{:.3f}\".format(K), \"mol / lit / min\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "For second order reaction,\n", "t0.5 = 1 / Ka\n", "The rate constant is 0.333 mol / lit / min\n" ] } ], "prompt_number": 23 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem: 8, Page no: 151" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import log\n", "\n", "# Variables\n", "T = 500 # C\n", "Pi = 350 # torr\n", "r1 = 1.07 # torr / s\n", "r2 = 0.76 # torr / s\n", "\n", "# Solution\n", "print \"1.07 = k(0.95a)^n\"\n", "print \"0.76 = k(0.80a)^n\"\n", "n = log(r1 / r2) / log(0.95 / 0.80)\n", "print \"Hence, order of reaction is\", round(n)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "1.07 = k(0.95a)^n\n", "0.76 = k(0.80a)^n\n", "Hence, order of reaction is 2.0\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem: 9, Page no: 152" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Solution\n", "print \"Applying steady state approximation to the concentration of NOCl2,\",\n", "print \"we get\"\n", "print \"d[NOCl2] / dt = 0 = k1 [NO] [Cl2] - k-1 [NOCl2] - k2 [NO] [NOCl2]\"\n", "print \"[NOCl2] = k1 [NO] [Cl2] / (k-1 + k2 [NO])\"\n", "print \"Now, the overall rate of reaction,\"\n", "print \"d[NOCl2] / dt = k2 [NO] [NOCl2]\"\n", "print \"From the above equations we get,\"\n", "print \"(k1 k2 / k-1) * [NO]^2 * [Cl2], if k2[NO] << k-1\"\n", "print \"k [NO]^2[Cl2], where k = k1 * k2 / k-1\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Applying steady state approximation to the concentration of NOCl2, we get\n", "d[NOCl2] / dt = 0 = k1 [NO] [Cl2] - k-1 [NOCl2] - k2 [NO] [NOCl2]\n", "[NOCl2] = k1 [NO] [Cl2] / (k-1 + k2 [NO])\n", "Now, the overall rate of reaction,\n", "d[NOCl2] / dt = k2 [NO] [NOCl2]\n", "From the above equations we get,\n", "(k1 k2 / k-1) * [NO]^2 * [Cl2], if k2[NO] << k-1\n", "k [NO]^2[Cl2], where k = k1 * k2 / k-1\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem: 10, Page no: 153" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import log10\n", "\n", "# Constant\n", "R = 1.987 # cal / K / mol\n", "\n", "# Variables\n", "K2_K1 = 4 # factor increase\n", "T1 = 27 # C\n", "T2 = 47 # C\n", "\n", "# Solution\n", "T1 += 273.0\n", "T2 += 273.0\n", "Ea = log10(4) * 2.303 * R * (T1 * T2 / (T2 - T1))\n", "print \"The activation energy for the reaction is\", \"{:.2e}\".format(Ea),\n", "print \"cal /mol\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The activation energy for the reaction is 1.32e+04 cal /mol\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem: 11, Page no: 153" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import log10\n", "\n", "# Variables\n", "a = 1 # mole\n", "x = 3 / 4.0 # reaction completed\n", "\n", "# Solution\n", "K = (2.303 / 6) * log10(1 / (1 - x))\n", "print \"The rate constant is\", \"{:.3f}\".format(K), \"/min\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The rate constant is 0.231 /min\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem: 12, Page no: 153" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import log10\n", "\n", "# Solution\n", "print \"Let the initial concentration be 100, when x = 25\",\n", "print \" t = 30 minutes\"\n", "a = 100\n", "x = 25.0\n", "t = 30 # minutes\n", "K = 2.303 / t * log10(a / (a - x))\n", "t05 = 0.683 / K\n", "t = 2.303 / K * log10(a / x)\n", "print \"K =\", \"{:.2e}\".format(K), \"/ min\"\n", "print \"T0.5 =\", \"{:.2f}\".format(t05), \"min\"\n", "print \"t =\", \"{:.1f}\".format(t), \"min\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Let the initial concentration be 100, when x = 25 t = 30 minutes\n", "K = 9.59e-03 / min\n", "T0.5 = 71.21 min\n", "t = 144.6 min\n" ] } ], "prompt_number": 15 } ], "metadata": {} } ] }