# Chapter 11 Thermodynamics Some Basic Concepts¶

## Example 11.1 , Page no:259¶

In [1]:
import math
from __future__ import division

#initialisation of variables
T= 25 #C
T1= 75 #C
k= 6.45 #cal per mole per degree
k1= 1.41*10**-3 #cal per mole per degree k^-1
k2= -8.1*10**-8 #cal per mole per degree k^-2
m= 14 #gms
M= 28 #gms

#CALCULATIONS
Cp= k+k1*(273+T)+k2*(273+T)**2
Cp1= k+k1*(273+T1)+k2*(273+T1)**2
cp= (Cp+Cp1)/2
H= (m/M)*cp*(T1-T)
H1= (m/M)*(k*(T1-T)+(k1/2)*((273+T1)**2-(273+T)**2)+(k2/3)*((273+T1)**3-(273+T)**3))
#RESULTS
print"Heat required=",round(H,1),"cal";
print"value of dH=",round(H1,1),"cal";

Heat required= 172.4 cal
value of dH= 172.4 cal


## Example 11.2 , Page no:260¶

In [2]:
import math
from __future__ import division

#initialisation of variables
m= 64 #gms
M= 32 #gms
T= 100 #C
T1= 0 #C
cp= 7.05 #cal per mole per degree
cp1= 5.06 #cal per mole per degree

#CALCULATIONS
H= cp*(m/M)*(T-T1)
E= cp1*(m/M)*(T-T1)

#RESULTS
print"value of dH=",round(H),"cal";
print"value of dE=",round(E),"cal";

value of dH= 1410.0 cal
value of dE= 1012.0 cal


## Example 11.3 , Page no:261¶

In [3]:
import math
from __future__ import division

#initialisation of variables
n= 2 #moles
R= 1.99 #cal er mole per degree
T= 80 #C
H1= 94.3 #cal per gram
M= 78 #gms per mole

#CALCULATIONS
w= n*R*(273+T)
H= n*M*H1
E= H-w

#RESULTS
print"value of dH=",round(H),"cal";
print"value of dE=",round(E),"cal";

value of dH= 14711.0 cal
value of dE= 13306.0 cal


## Example 11.4 , Page no:262¶

In [4]:
import math
from __future__ import division

#initialisation of variables
m= 9 #gms
T= -10 #C
T1= 0 #C
R= 0.5 #cal per gram per degree
H= 79.7 #cal per gram
R1= 1 #cal per gram per degree
T2= 100 #C
H1= 539.7 #cal per gm
R2= 8.11 #cal per gram per degree
M= 18 #gms
T3= 40 #C

#CALCULATIONS
dH= m*R*(T1-T)
dH1= m*H
dH2= m*R1*(T2-T1)
dH3= m*H1
dH4= (m/M)*R2*(T3-T1)
dH5= dH+dH1+dH2+dH3+dH4

#RESULTS
print"value of dH=",round(dH5,1),"cal";

value of dH= 6681.8 cal