comparison of stoichiometric combustion coeffcient with number of moles of carbon for different types of fuels alkanes, alkenes and alkynes using Octave coding

Objective: To plot the comparison of stochiometric coeffcient of oxygen versus number of moles of carbon for different types of fuel

theory:

combustion equations

Alkane (CnH2n+2):

`C_n H_(2n+2)+ar(O_2+3.76N_2 )=aCO_2+bH_2 O+c(3.76N_2)`

balancing the above equation,

For carbon ,`a=n`

For hydrogen balance,`b=n+1`

For nitrogen balance `c=ar`

For oxygen balance `ar=a+b/2=n+((n+1))/2=(3n+1)/2`

alkene equation:

`C_n H_2n+ar(O_2+3.76N_2 )=aCO_2+bH_2 O+c(3.76N_2)`

balancing the above equation,

For carbon ,`a=n`

For hydrogen balance,`b=n`

For nitrogen balance `c=ar`

For oxygen balance `ar=a+b/2=n+n/2=3n/2`

alkene equation:

Alkyne (CnH2n-2):

`C_n H_(2n-2)+ar(O_2+3.76N_2 )=aCO_2+bH_2 O+c(3.76N_2)`

balancing the above equation,

For carbon ,`a=n`

For hydrogen balance,`b=n-1`

For nitrogen balance `c=ar`

For oxygen balance `ar=a+b/2=n+((n-1))/2=(3n-1)/2`

clear all
close all
clc


%n = number of moles
n = 1:10;

%for alkane, CnH2n+2 + ar*(O2 + 3.76*N2) = a*CO2 + b*H2O + c*3.76*N2
% For balancing this equation, 
% a = n       (C balance)
% b = (n+1)   (H2 balance)
% c = ar        (N2 balance)
% ar = a+b/2 = n+(n+1/2) (O2 balance)
% ar = (3*n+1)/2

ar_alkane = 1.5*n+0.5;

%for alkene, CnH2n + ar*(O2 + 3.76*N2) = n*CO2 + n*H2O + ar*3.76*N2
% Therefore ar = a+b/2 = n+n/2
% ar = 2n

ar_alkene = 1.5*n;

%for alkyne, CnH2n-2 + ar*(O2 + 3.76*N2) = n*CO2 + (n-1)*H2O + ar*3.76*N2
% Therefore ar = a+b/2 = n+(n-1)/2
% ar = (3*n-1)/2

ar_alkyne = 1.5*n-0.5;


%plotting
plot (n,ar_alkane,'r', n,ar_alkene,'b', n,ar_alkyne,'g')
legend('Alkane', 'Alkene', 'Alkyne')

%labelling
xlabel("Number of moles of Carbon")
ylabel("Stoiciometric coefficient")

conclusion:

The program was run for Carbon atoms ranging from 1 to 10 for all alkanes, alkenes and alkynes and it was noted that the stochiometric ratio varied linearly with carbon moles.