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diff --git a/479/CH13/EX13.1/Example_13_1.sce b/479/CH13/EX13.1/Example_13_1.sce
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@@ -0,0 +1,30 @@
+//Chemical Engineering Thermodynamics

+//Chapter 13

+//Thermodynamics in Phase Equilibria

+

+//Example 13.1

+clear;

+clc;

+

+//Given

+//N2 obeys the relation : Z = 1+(2.11*10^-4*P)

+Tc = 126;//Critical temperature in K

+Pc = 33.5;//Critical pressure in atm

+T = 373;//in K

+P = 100;//in atm

+

+//To Calculate the fugacity of N2 at 373K and 100 atm

+//(i)Using the Z relation given above

+//From equation 13.12 (page no 239)

+phi = %e^(2.11*10^-4*(P-0));//fugacity coefficient

+f = phi*P;

+mprintf('(i)The fugacity of N2 using the given Z relation is %f atm',f);

+

+//(ii)Using the fugacity chart given in figure A.2.9

+Pr = P/Pc;//Reduced pressure in atm

+Tr = T/Tc;//Reduced temperature in K

+//From figure A.2.9,

+phi = 1.04

+f = phi*P;

+mprintf('\n (ii)The fugacity of N2 using the fugacity chart is %f atm',f);

+//end
\ No newline at end of file
diff --git a/479/CH13/EX13.10/Exampe_13_10.sce b/479/CH13/EX13.10/Exampe_13_10.sce
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index 000000000..e6a74d9ba
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+//Chemical Engineering Thermodynamics

+//Chapter 13

+//Thermodynamics in Phase Equilibria

+

+//Example 13.10

+clear;

+clc;

+

+//Given

+//The given example is a theoretical problem and does not involve any numerical computation

+//end
\ No newline at end of file
diff --git a/479/CH13/EX13.11/Example_13_11.sce b/479/CH13/EX13.11/Example_13_11.sce
new file mode 100755
index 000000000..dbd0fb26e
--- /dev/null
+++ b/479/CH13/EX13.11/Example_13_11.sce
@@ -0,0 +1,11 @@
+//Chemical Engineering Thermodynamics

+//Chapter 13

+//Thermodynamics in Phase Equilibria

+

+//Example 13.11

+clear;

+clc;

+

+//Given

+//The given example is a theoretical problem and does not involve any numerical computation

+//end
\ No newline at end of file
diff --git a/479/CH13/EX13.12/Example_13_12.sce b/479/CH13/EX13.12/Example_13_12.sce
new file mode 100755
index 000000000..c31b3fdf3
--- /dev/null
+++ b/479/CH13/EX13.12/Example_13_12.sce
@@ -0,0 +1,31 @@
+//Chemical Engineering Thermodynamics

+//Chapter 13

+//Thermodynamics in Phase Equilibria

+

+//Example 13.12

+clear;

+clc;

+

+//Given

+x_A = [0 0.0435 0.0942 0.1711 0.2403 0.3380 0.5981];//mole fraction of acetic acid

+p_A = [0 17.2 30.5 46.5 57.8 69.3 95.7];//partial pressure of acetic acid in mmHg

+P_T1 = 202;//vapour pressure of toulene in mmHg

+P_T2_ex = 167.3;//experimental partial pressure in mmmHg

+

+//To Calculate the partial pressure of toulene in the solution and check with the experimental value

+//From the equation 13.95,

+//ln(P_T2/P_T1) = -intg(x_A/((1-x_A)*p_A))

+for i = 1:7

+    if (p_A(i) ~= 0)

+    x(i) = (x_A(i)/((1-x_A(i))*p_A(i)))*10^4

+    end

+end

+plot(x,p_A);

+xtitle(" ","(x_A/((1-x_A)*p_A))*10^4", "p_A");

+//Area of the graph drawn is

+A = -0.138;

+P_T2 = (%e^A)*P_T1;

+e = ((P_T2-P_T2_ex)*100)/P_T2_ex;

+mprintf('The partial pressure of toulene is %f mmHg',P_T2);

+mprintf('\n This deviates %i percent from the reported value',e);

+//end
\ No newline at end of file
diff --git a/479/CH13/EX13.13/Example_13_13.sce b/479/CH13/EX13.13/Example_13_13.sce
new file mode 100755
index 000000000..8360364b0
--- /dev/null
+++ b/479/CH13/EX13.13/Example_13_13.sce
@@ -0,0 +1,43 @@
+//Chemical Engineering Thermodynamics

+//Chapter 13

+//Thermodynamics in Phase Equilibria

+

+//Example 13.13

+clear;

+clc;

+

+//Given

+P = 760;//pressure at maximum boiling azeotrope of A and B in mmHg

+x_A = 0.6;//mole fraction of A in liquid phase

+x_B = 0.4;//mole fraction of B in liquid phase

+p_A = 600;//vapour pressure of A at 90 deg cel

+p_B = 300;//vapour pressure of B at 90 deg cel

+

+//To Check whether the activity coefficient of the solution can be represented by the Margules equation

+y_A = P/p_A;//Activity coefficient of A

+y_B = P/p_B;//Activity coefficient of B

+//From the Margules equation or equation (a) & (b)

+U = [((x_B^2)-(2*(x_B^2)*x_A)) (2*(x_B^2)*x_A); (2*(x_A^2)*x_B) ((x_A^2)-(2*(x_A^2)*x_B))];

+V = [log(y_A); log(y_B)];

+W = U\V;

+//Now the value of constants A and B in equations(a)&(b) are given as

+A = W(1);

+B = W(2);

+//let us assume 

+x_A = [0.0 0.2 0.4 0.6 0.8 1.0];

+x_B = [1.0 0.8 0.6 0.4 0.2 0.0];

+//C = lny_A; D = lny_B; E = ln(y_A/y_B)

+for i = 1:6

+    C(i) = (x_B(i)^2)*(2*(B-A)*x_A(i)+A);

+    D(i) = (x_A(i)^2)*(2*(A-B)*x_B(i)+B);

+    E(i) = C(i)-D(i);

+end

+clf;

+plot(x_A,E);

+xtitle(" ","x_A","ln(y_A/y_B)");

+a = get("current_axes");

+set(a,"x_location","origin");

+//Since the graph drawn is approximately symmetrical.Thus it satisfies the Redlich-Kister Test

+mprintf('The actvity coefficients of the system can be represented by Margules equation');

+//end

+

diff --git a/479/CH13/EX13.14/Example_13_14.sce b/479/CH13/EX13.14/Example_13_14.sce
new file mode 100755
index 000000000..5c812b361
--- /dev/null
+++ b/479/CH13/EX13.14/Example_13_14.sce
@@ -0,0 +1,28 @@
+//Chemical Engineering Thermodynamics

+//Chapter 13

+//Thermodynamics in Phase Equilibria

+

+//Example 13.14

+clear;

+clc;

+

+//Given

+P = 760;//Total pressure of the mixture in mmHg

+T = [80 90 95 100];//Temperature in deg celsius

+P1 = [87.4 129.0 162.0 187.0];//vapour pressure of 1,1,2,2-tetrachloroethane in mmHg

+P2 = [356 526 648 760];//Vapour pressure of water in mmHg

+

+//To Calculate the composition of the vapour evolved

+clf;

+plot2d(T,P1,style=3);

+plot2d(T,P2,style=5);

+xtitle(" ","Temp in deg cel","Vapour pressure in mmHg");

+legend("1,1,2,2-tetrachloroethane","Water");

+//From the graph we conclude that at 93.8 deg cel

+P1 = 155;//in mm Hg

+P2 = 605;//in mm Hg

+y_1 = P1/P;

+y_2 = P2/P;

+mprintf('Mole fraction of 1,1,2,2-tetrachloroethane in vapour is %f',y_1);

+mprintf('\n Mole fraction of water in vapour is %f',y_2);

+//end
\ No newline at end of file
diff --git a/479/CH13/EX13.15/Example_13_15.sce b/479/CH13/EX13.15/Example_13_15.sce
new file mode 100755
index 000000000..bcf443b19
--- /dev/null
+++ b/479/CH13/EX13.15/Example_13_15.sce
@@ -0,0 +1,30 @@
+//Chemical Engineering Thermodynamics

+//Chapter 13

+//Thermodynamics in Phase Equilibria

+

+//Example 13.15

+clear;

+clc;

+

+//Given

+T = [146.2 142.3 126.1 115.9 95.0 98.0 100];//Temperature in deg cel

+P1 = [760.0 685.0 450.3 313.0];//Vapour pressure of 1,1,2,2-tetrachloroethane at the coressponding temperature in mm Hg

+P2_5 = 648.0;//Vapour pressure of water at 95 deg cel in mm Hg

+P2_6 = 711.0;//Vapour pressure of water at 98 deg cel in mm Hg

+P = 760;//Total pressure of mixture in mm Hg

+

+x1 = [0 0 0 0 0 0 0];

+//To plot a graph between temperature and vapour phase composition

+for i = 1:4

+    x1(i) = P1(i)/P;//mole fraction of 1,1,2,2-tetrachloroethane

+end

+x2_5 = P2_5/P;//mole fraction of water at 95 deg cel

+x2_6 = P2_6/P;//mole fraction of water at 98 deg cel

+x1(5) = 1-x2_5;

+x1(6) = 1-x2_6;

+

+clf;

+plot(x1,T);

+xtitle("","mole fraction of 1,1,2,2-tetrachloroethane","Temperature in deg cel");

+mprintf('The required graph has been ploted in the graphic window');

+//end
\ No newline at end of file
diff --git a/479/CH13/EX13.16/Example_13_16.sce b/479/CH13/EX13.16/Example_13_16.sce
new file mode 100755
index 000000000..fd786013e
--- /dev/null
+++ b/479/CH13/EX13.16/Example_13_16.sce
@@ -0,0 +1,48 @@
+//Chemical Engineering Thermodynamics

+//Chapter 13

+//Thermodynamics in Phase Equilibria

+

+//Example 13.16

+clear;

+clc;

+

+//Given

+//B = -(1.203*10^10)*(T^2.7); second virial coefficient, T is in K

+//log P = 6.95464-(1344.8/(219.482+t))...(a);Vapour pressure of toulene

+t = 107.2;//Temperature in deg cel

+T = t+273.16;//in K

+H_ex = 7964;//experimental value of heat of vapourisation in Kcal/Kgmole

+d = 800;//density of liquid toulene in Kg/cubic meter

+R = 1.98;//gas constant in Kcal/Kgmole K

+M = 92.14;//molecular weight of toulene

+

+//To Calculate the heat of vapourization of toulene by using ideal gas law, second virial coefficient but neglecting vl and including vl

+//From equation (a), let K = dlogP/dT

+K = 1344.8/(219.482+t)^2;

+//(i)Using ideal gas behaviour

+//From equation 13.112(page no 286)

+H_c = (2.303*R*(T^2))*K;

+mprintf('(i)The heat of vapourization  using ideal gas behaviour is %f Kcal/Kgmole',H_c);

+D = ((H_c-H_ex)/H_c)*100;

+mprintf('\n    The deviation is %f percent',D);

+

+//(ii)Using second virial coeff but neglecting vl

+//From equation(a)

+P = 10^(6.95464-1344.8/(219.482+t));//in mm Hg

+P1 = P*1.033*10^4/760;//in Kgf/sq m

+B = -((1.203*10^10)/(T^2.7))*10^-3;//in cubic meter/Kgmole

+//From equation 13.111 (page no 286) neglecting vl,

+l = (R*T)+((B*P1)/427);//in Kcal/Kgmole

+H_c = K*2.303*T*l;

+mprintf('\n\n(ii)The heat of vapourisation using second virial coefficient but neglecting vl is %f Kcal/Kgmole',H_c);

+D = ((H_c-H_ex)/H_c)*100;

+mprintf('\n    The deviation in this case is %f percent',D);

+

+//(iii)Using second virial coeff including vl

+vl = M/d;//Liquid specific volume in cubic meter/Kgmole

+n = P1*vl/427;//in Kcal/Kgmole

+H_c = K*2.303*T*(l-n);

+mprintf('\n\n(iii)The heat of vapourisation using second virial coefficient including vl is %f Kcal/Kgmole',H_c);

+D = ((H_c-H_ex)/H_c)*100;

+mprintf('\n     The deviation in this case is %f',D);

+//end
\ No newline at end of file
diff --git a/479/CH13/EX13.17/Example_13_17.sce b/479/CH13/EX13.17/Example_13_17.sce
new file mode 100755
index 000000000..02cb59dac
--- /dev/null
+++ b/479/CH13/EX13.17/Example_13_17.sce
@@ -0,0 +1,40 @@
+//Chemical Engineering Thermodynamics

+//Chapter 13

+//Thermodynamics in Phase Equilibria

+

+//Example 13.17

+clear;

+clc;

+

+//Given

+H_ex = 539;//Heat of vapoization of water in Kcal/Kg

+Tc = 647;//Critical temperature in K

+Pc = 218;//Critical pressure in atm

+Tb = 373;//Boiling point of water in K

+t = 100;//temperature in deg cel

+M = 18;//Molecular weight of water

+P = 1;//pressure at boiling point in atm

+P1 = 1.033*10^4;//pressure in Kgf/sq m

+

+//To Calculate the heat of vapourisation of water by Vishwanath and Kuloor method and by Riedel's method and compare with the experimental value

+//(i) Using Vishwanath and Kuloor method

+H_c = (4.7*Tc*((1-(P/Pc))^0.69)*log(P/Pc))/((1-(Tc/Tb))*18);

+mprintf('(i)The heat of vapourisation of water using Vishwanath and Kuloor method is %f Kcal/Kg',H_c);

+D = (H_c-H_ex)*100/H_c;

+mprintf('\n    The deviation occurs using this method is %f percent',D);

+

+//(ii)Using Riedel's method

+H_c = (Tb*2.17*(log(218)-1))/((0.93-(Tb/Tc))*18);

+mprintf('\n\n(ii)The heat of vapourisation of water using Riedel method is %f Kcal/Kg',H_c);

+D = (H_c-H_ex)*100/H_c;

+mprintf('\n    The deviation occurs using this method is %f percent',D);

+

+//(iii)By using given vapour equation; logP = 8.2157-(2218.8537/(273.16+t)), t is in deg cel

+//From steam table,

+Vv = 1.673;//in cubic meter/Kg

+Vl = 0.001;//in cubic meter/Kg

+H_c = (2218.8/(273.16+t)^2)*(2.3*Tb*P1*(Vv-Vl)/427);

+mprintf('\n\n(iii)The heat of vapourisation using the given vapour equation is %f Kcal/Kg',H_c);

+D = (H_c-H_ex)*100/H_c;

+mprintf('\n    The deviation occurs using this method is %f percent',D);

+//end
\ No newline at end of file
diff --git a/479/CH13/EX13.17/Example_13_17.txt b/479/CH13/EX13.17/Example_13_17.txt
new file mode 100755
index 000000000..59ddec64e
--- /dev/null
+++ b/479/CH13/EX13.17/Example_13_17.txt
@@ -0,0 +1,3 @@
+For example 13.17(i), the answer given in the book, heat of vapourisation H_c = 532Kcal/Kg and the deviation as 1.3 %

+		      but i am getting H_c = 1234.397 Kcal/Kg,using the Vishwanath and Kuloor method

+		      and the deviation is 56.335 %.There might be some calculation mistake in the book.		
\ No newline at end of file
diff --git a/479/CH13/EX13.18/Example_13_18.sce b/479/CH13/EX13.18/Example_13_18.sce
new file mode 100755
index 000000000..748a8434e
--- /dev/null
+++ b/479/CH13/EX13.18/Example_13_18.sce
@@ -0,0 +1,33 @@
+//Chemical Engineering Thermodynamics

+//Chapter 13

+//Thermodynamics in Phase Equilibria

+

+//Example 13.18

+clear;

+clc;

+

+//Given

+T1 = 273-87;//temp in K

+T2 = 273;//temp in K

+H1 = 115;//Latent heat of saturated ethane at 1 atm and -87 deg cel in Kcal/Kg

+H2_ex = 72.44;//Experimental value of latent heat at 0 deg cel in Kcal/Kg

+Tc = 306;//Critical temperature in K

+M = 30;//Molecular weight of ethane

+

+//To Calculate the latent heat of saturated ethane at 0 deg cel

+Tr1 = T1/Tc;//reduced temp in K

+Tr2 = T2/Tc;//reduced temp in K

+//(i)Using Waton's method:

+H2_c = H1*((1-Tr2)/(1-Tr1))^0.38;

+mprintf('(i)The latent heat of saturated ethane at 0 deg cel using Waton method is %f Kcal/Kg',H2_c);

+D = (H2_ex-H2_c)*100/H2_ex;

+mprintf('\n   The deviation occurs using this method is %f percent',D);

+

+//(ii)Using Vishwanath and Kuloor method

+//From equation 13.117 (page no 289)

+n = (0.00133*(H1*M/T1)+0.8794)^(1/0.1);

+H2_c = H1*((1-Tr2)/(1-Tr1))^n;

+mprintf('\n\n(ii)The latent heat of saturated ethane at 0 deg cel using Vishwanath and Kuloor method is %f Kcal/Kg',H2_c);

+D = (H2_ex-H2_c)*100/H2_ex;

+mprintf('\n   The deviation occurs using this method is %f percent',D);

+//end
\ No newline at end of file
diff --git a/479/CH13/EX13.19/Example_13_19.sce b/479/CH13/EX13.19/Example_13_19.sce
new file mode 100755
index 000000000..09dfa1409
--- /dev/null
+++ b/479/CH13/EX13.19/Example_13_19.sce
@@ -0,0 +1,36 @@
+//Chemical Engineering Thermodynamics

+//Chapter 13

+//Thermodynamics in Phase Equilibria

+

+//Example 13.19

+clear;

+clc;

+

+//Given

+H_s_ex = 32.7;//experimental value of latent heat of the solution in KJ/mole

+x1 = 0.536;//mole percent of toulene in the solution

+x2 = 1-0.536;//mole percent of 1,1,1-trichloroethane in the solution

+H1 = 33.34;//Latent heat of toulene in KJ/gmole

+H2 = 29.72;//Latent heat of 1,1,1-trichloroethane in KJ/gmole

+He = 0;//excess enthalpy is neglected

+Cp1 = 39.55;//Specific heat of toulene in cal/gmole deg cel

+Cp2 = 24.62;//Specific heat of 1,1,1-trichloroethane in cal/gmole deg cel

+T_D = 100;//dew point temperature in deg cel

+T_B = 92.6;//bubble point temperature in deg cel

+

+//To calculate the latent heat of the solution and compare it with the one which calculated from the given vapour pressure equation

+//(i)Calculation of latent heat of the solution

+//From equation 13.118 (page no 291)

+H_s = H1*x1+H2*x2+He+(Cp1*x1+Cp2*x2)*10^-3*4.17*(T_D-T_B);

+mprintf('(i)The latent heat of the solution is %f KJ/gmole',H_s);

+D = ((H_s_ex-H_s)*100)/H_s_ex;

+mprintf('\n    The deviation occurs using this method is %f percent',D);

+

+//(ii)Calculation of latent heat from the vapour pressure equation

+//From equation (a) (page no 291)

+K = 1657.599/((273.16+5)^2);

+H_s = (K*2.303*8.314*(273.16+5)^2)*10^-3;

+mprintf('\n\n(ii)The latent heat of the solution is %f KJ/gmole',H_s);

+D = ((H_s_ex-H_s)*100)/H_s_ex;

+mprintf('\n    The deviation occurs using this method is %f percent',D);

+//end
\ No newline at end of file
diff --git a/479/CH13/EX13.19/Example_13_19.txt b/479/CH13/EX13.19/Example_13_19.txt
new file mode 100755
index 000000000..aeffb16d5
--- /dev/null
+++ b/479/CH13/EX13.19/Example_13_19.txt
@@ -0,0 +1,4 @@
+For example 13.19, the answer given in the book in part(i), deviation as 0.91% but i am getting deviation as 0.1%.

+		   and for part(ii) i am getting heat of vapourization as 31.74 KJ/gmole and deviation as 2.94%.

+		   but in the book it is given as heat of vapourization as 32.1 KJ/gmole and deviation as 1.8%.

+		   There might be some calculation mistake in the book.
\ No newline at end of file
diff --git a/479/CH13/EX13.2/Example_13_2.sce b/479/CH13/EX13.2/Example_13_2.sce
new file mode 100755
index 000000000..a770036e1
--- /dev/null
+++ b/479/CH13/EX13.2/Example_13_2.sce
@@ -0,0 +1,22 @@
+//Chemical Engineering Thermodynamics

+//Chapter 13

+//Thermodynamics in Phase Equilibria

+

+//Example 13.2

+clear;

+clc;

+

+//Given

+P1 = 50*1.03*10^4;//Initial pressure in Kgf/sq m

+T = 373;//Temperature in K

+P2 = 1.03*10^4;//Final pressure in Kgf/sq m

+V = 0.001*18;//Volume in cubic meter

+R = 848;//gas constant in m Kgf/Kgmole K

+

+//To Calculate the fugacity of liquid water

+//From equation 13.13(page no 240)

+del_u = (V/(R*T))*(P2-P1);//del_u = ln(f2/f1); Change in chemical potential

+f1 = P2;//in Kgf/sq m

+f2 = f1*(%e^del_u);

+mprintf('The fugacity of the liquid water at 50 atm is %4.2e Kgf/sq m',f2);

+//end
\ No newline at end of file
diff --git a/479/CH13/EX13.3/Example_13_3.sce b/479/CH13/EX13.3/Example_13_3.sce
new file mode 100755
index 000000000..cfe3f9ae3
--- /dev/null
+++ b/479/CH13/EX13.3/Example_13_3.sce
@@ -0,0 +1,27 @@
+//Chemical Engineering Thermodynamics

+//Chapter 13

+//Thermodynamics in Phase Equilibria

+

+//Example 13.3

+clear;

+clc;

+

+//Given

+x1 = 0.1;//mole fraction of methane

+x2 = 0.9;//mole fraction of propane

+P = [28.1 31.6 35.1];//Pressure in Kgf/sq cm are

+K1 = [5.8 5.10 4.36];//Vapourisation constants of methane at the corresponding presssures

+K2 = [0.61 0.58 0.56];//Vapourisation constants of propane at the correspondig pressures

+

+//To Calculate the bubble point pressure of the solution

+//From equation 13.27 (page no 245)

+for i = 1:3

+    y1(i) = K1(i)*x1;//mole fraction of methane in the vapour phase

+    y2(i)= K2(i)*x2;//mole fraction of propane in the vapour phase

+    y(i) = y1(i)+y2(i);//sum of the mole fraction in the vapour phase

+end

+plot(P,y);

+xtitle("y vs pressure","P","y");

+P1 = interpln([y';P],1);// in Kgf/sq cm

+mprintf('The bubble point pressure of the solution is %f Kgf/sq cm',P1);

+//end
\ No newline at end of file
diff --git a/479/CH13/EX13.4/Example_13_4.sce b/479/CH13/EX13.4/Example_13_4.sce
new file mode 100755
index 000000000..5c1116c47
--- /dev/null
+++ b/479/CH13/EX13.4/Example_13_4.sce
@@ -0,0 +1,37 @@
+//Chemical Engineering Thermodynamics

+//Chapter 13

+//Thermodynamics in Phase Equilibria

+

+//Example 13.4

+clear;

+clc;

+

+//Given

+T = [80.6 79.0 77.3 61.4];//Various temperature in deg cel

+x1 = [0.0 15.0 29.0 100.0];//mole fraction of CHCl3 in liquid phase

+y1 = [0.0 20.0 40.0 100.0];//mole fraction of CHCl3 in vapour phase

+P1 = [1370 1310 1230 700];//Vapour pressure of CHCl3 in mm Hg

+P = 760;//Total pressure in mm Hg

+

+//To Calculate the equilibrium data i.e y/x and compare with the experimental values

+//From equation 13.27 (page no 245);K = y1/x1 = Pi/P

+mprintf('Temperature    Experimental   Calculated');

+

+for i = 1:4

+    mprintf('\n %f',T(i));

+    if x1(i) == 0 

+        mprintf('     Not defined');

+        else

+ K_ex(i) = y1(i)/x1(i);

+mprintf('        %f',K_ex(i));

+ end

+K_c(i) = P1(i)/P;

+mprintf('      %f',K_c(i));

+end

+

+if K_ex(i) == K_c(i) 

+    then mprintf('\n\n The liquid solution is perfect');

+else

+    mprintf('\n\n The liquid solution is imperfect');

+end

+//end
\ No newline at end of file
diff --git a/479/CH13/EX13.5/Example_13_5.sce b/479/CH13/EX13.5/Example_13_5.sce
new file mode 100755
index 000000000..72f3a8d68
--- /dev/null
+++ b/479/CH13/EX13.5/Example_13_5.sce
@@ -0,0 +1,11 @@
+//Chemical Engineering Thermodynamics

+//Chapter 13

+//Thermodynamics in Phase Equilibria

+

+//Example 13.5

+clear;

+clc;

+

+//Given

+//The given example is a theoretical problem and does not contain any numerical computation

+//end
\ No newline at end of file
diff --git a/479/CH13/EX13.6/Example_13_6.sce b/479/CH13/EX13.6/Example_13_6.sce
new file mode 100755
index 000000000..990304a97
--- /dev/null
+++ b/479/CH13/EX13.6/Example_13_6.sce
@@ -0,0 +1,24 @@
+//Chemical Engineering Thermodynamics

+//Chapter 13

+//Thermodynamics in Phase Equilibria

+

+//Example 13.6

+clear;

+clc;

+

+//Given

+x1 = 0.1;//Mole fraction of dichloromethane (CCl2H2)

+x2 = 0.9;//Mole fraction of methyl acetate (C3H6O2)

+M1 = 85;//Molecular weight of CCl2H2

+M2 = 74;//Molecular weight of C3H602

+D1 = 1.3163;//Density of CCl2H2 in gm/cc

+D2 = 0.9279;//Density of C3H6O2 in gm/cc

+

+//To Calculate the volume of 10% dichloromethane solution

+V1 = M1/D1;//Specific volume of pure CCL2H2 in cc/gmole

+V2 = M2/D2;//Specific volume of C3H6O2 in cc/gmole

+//From equation 13.62(page no 256)& 13.78 (page no 257)

+V_e = x1*x2*(1.2672-0.771*x1);//excess volume in cc/gmole

+V = V1*x1+V2*x2+V_e;

+mprintf('The volume of 10 percent dichloromethane is %f cc/gmole',V);

+//end
\ No newline at end of file
diff --git a/479/CH13/EX13.7/Example_13_7.sce b/479/CH13/EX13.7/Example_13_7.sce
new file mode 100755
index 000000000..695af3a9d
--- /dev/null
+++ b/479/CH13/EX13.7/Example_13_7.sce
@@ -0,0 +1,52 @@
+//Chemical Engineering Thermodynamics

+//Chapter 13

+//Thermodynamics in Phase Equilibria

+

+//Example 13.7

+clear;

+clc;

+

+//Given

+x_T = 0.957;//mole fraction of Toluene

+x_D = 0.043;//mole fraction of 1,2-dichloroethane

+t = [90; 100; 110];//temperature in deg cel

+R = 1.98;//gas constant in Kcal/Kgmole K

+

+//To Calculate the vapour pressure of the solution, bubble point at 686 mm Hg and the vapour composition at equilibrium,

+//compare the experimental value of 91.2% toluene in vapour with the calculated value & calculate the free energy of mixing

+//(1)Calculation of vapour pressure

+mprintf('(1)Temp(deg cel)    P_T(mmHg)          P_D(mmHg)           P_s(mmHg)');

+for i = 1:3

+    P_T(i) = 10^(6.95464-(1344.8/(219.482+t(i))));//Given as equation(a)(page no 260)

+    P_D(i) = 10^(7.03993-(1274.079/(223+t(i))));//Given as equation(b)(page no 260)

+    P_s(i) = x_T*P_T(i)+x_D*P_D(i);//pressure of the solution in mm Hg

+    mprintf('\n   %f',t(i));

+    mprintf('          %f',P_T(i));

+    mprintf('        %f',P_D(i));

+    mprintf('         %f',P_s(i));

+end 

+

+//(2)Calculation of bubble point and comparison of values

+clf;

+plot(t,P_s);

+xtitle("t vs P_s","t","P_s");

+T = interpln([P_s';t'],686);

+P = 686;//pressure of solution in mm Hg

+y_T_e = 0.912;//experimental value of mole fraction of toluene

+//From the graph we found that the temperature at P = 686 mm Hg is

+//t = 105.3;//in deg cel

+mprintf('\n\n(2)The bubble point is %f deg cel',T);

+//From equation (a)(page no 260)

+P_T = 10^(6.95464-(1344.8/(219.482+T)));//vapour pressure of Toluene in mmHg

+//From equation 13.27 (page no 245)

+y_T_c = (x_T*P_T)/P;

+y_D_c = 1-y_T_c;

+mprintf('\n  The vapour composition of toluene is %f',y_T_c);

+mprintf('\n  The vapour composition of 1,2-dichloroethane is %f',y_D_c);

+e = ((y_T_e-y_T_c)/y_T_e)*100;

+mprintf('\n The percentage error is %f percent',e);

+

+//(3)Calculation of free energy

+del_F = R*(T+273)*((x_T*log(x_T))+(x_D*log(x_D)));

+mprintf('\n\n(3)The free energy of mixing is %f Kcal/Kgmole',del_F);

+//end
\ No newline at end of file
diff --git a/479/CH13/EX13.8/Example_13_8.sce b/479/CH13/EX13.8/Example_13_8.sce
new file mode 100755
index 000000000..2699ffb34
--- /dev/null
+++ b/479/CH13/EX13.8/Example_13_8.sce
@@ -0,0 +1,26 @@
+//Chemical Engineering Thermodynamics

+//Chapter 13

+//Thermodynamics in Phase Equilibria

+

+//Example 13.8

+clear;

+clc;

+

+//Given

+//Consider the diagram shown in page no 263

+w1 = 100;//weight of LiBr entered as feed in the evaporator per hour in Kg

+x1 = 0.45;//weight  fraction of LiBr entered as feed

+x2 = 0;//weight fraction of steam in the LiBr soln

+x3 = 0.65;//weight fraction of LiBr formed as product

+H1 = -39;//Enthalpy of 45% solution at 25 deg cel in Kcal/Kg

+H3 = -4.15;//Enthalpy of 65% solution at 114.4 deg cel in Kcal/Kg

+H2 = 649;//Enthalpy of superheated steam at 100 mmHg and 114.4 deg cel in Kcal/Kg

+

+//To Calculate the heating load required for the process

+//According to material balance

+w3 = (w1*x1)/x3;//weight of LiBr solution formed after evaporation per hour in Kg

+w2 = w1-w3;// weight of steam formed in Kg/hr

+//According to energy balance

+Q = (w2*H2)+(w3*H3)-(w1*H1);

+mprintf('The heat that has to be supplied for this concentration process is %f Kcal/hr',Q);

+//end
\ No newline at end of file
diff --git a/479/CH13/EX13.9/Example_13_9.sce b/479/CH13/EX13.9/Example_13_9.sce
new file mode 100755
index 000000000..b260581f6
--- /dev/null
+++ b/479/CH13/EX13.9/Example_13_9.sce
@@ -0,0 +1,11 @@
+//Chemical Engineering Thermodynamics

+//Chapter 13

+//Thermodynamics in Phase Equilibria

+

+//Example 13.9

+clear;

+clc;

+

+//Given

+// In the given example, all the values were determined from the graph given as figure 13.9 and it does not involve any numerical computation

+//end
\ No newline at end of file