How do I get my code to read CA3 and so on?

I have the following code entered so far, but it refuses to read past the if statement. How do I get the code to recognize my else statement?

V = 4 %m^3, Volume;
Vo = 0.04 %m^3/s;
T = V/Vo %s, Time constant;
k = 0.01 %m^3/mol/s, Rate constant;
CA0 = input('The value of the inlet concentration (CA0) is: ');
CA1 = ((1 + 2 * T * k * CA0)- sqrt(1 + 4 * T * k * CA0)) / (2 * T * k);
CA2 = ((1 + 2 * T * k * CA1)- sqrt(1 + 4 * T * k * CA1)) / (2 * T * k);
CA3 = ((1 + 2 * T * k * CA2)- sqrt(1 + 4 * T * k * CA2)) / (2 * T * k);
CA4 = ((1 + 2 * T * k * CA3)- sqrt(1 + 4 * T * k * CA3)) / (2 * T * k);
CA5 = ((1 + 2 * T * k * CA4)- sqrt(1 + 4 * T * k * CA4)) / (2 * T * k);
p = ['The value of CA1 is: ',num2str(CA1)];
    disp(p);
if (10 < CA1);
    disp('The final desired concentration has not been reached, moving to 2nd CSTR');
    p = ['The value of CA2 is: ',num2str(CA2)];
    disp(p);
else (10 < CA2);
    disp('The final desired concentration has not been reached, moving to 3rd CSTR');
    p = ['The value of CA3 is: ',num2str(CA3)];
    disp(p)
end

Answer 1

[Prathamesh]

Hi @Alex Wheeler,

I understand that the code you are executing is unable to run the “else” part.

The issue with the code is in the syntax of the “if-else” statement. In MATLAB, the “else” statement doesn't take a condition. It's a catch-all for when the “if” condition is false. To check another condition, you can use use “elseif”.

Here is an implementation of the same, in the given code snippet:

V = 4; %m^3, Volume
Vo = 0.04; %m^3/s
T = V/Vo; %s, Time constant
k = 0.01; %m^3/mol/s, Rate constant
CA0 = input('The value of the inlet concentration (CA0) is: ');
CA1 = ((1 + 2 * T * k * CA0)- sqrt(1 + 4 * T * k * CA0)) / (2 * T * k);
CA2 = ((1 + 2 * T * k * CA1)- sqrt(1 + 4 * T * k * CA1)) / (2 * T * k);
CA3 = ((1 + 2 * T * k * CA2)- sqrt(1 + 4 * T * k * CA2)) / (2 * T * k);
CA4 = ((1 + 2 * T * k * CA3)- sqrt(1 + 4 * T * k * CA3)) / (2 * T * k);
CA5 = ((1 + 2 * T * k * CA4)- sqrt(1 + 4 * T * k * CA4)) / (2 * T * k);

p = ['The value of CA1 is: ',num2str(CA1)];
disp(p);

if (10 < CA1)
    disp('The final desired concentration has not been reached, moving to 2nd CSTR');
    p = ['The value of CA2 is: ',num2str(CA2)];
    disp(p);
elseif (10 < CA2)
    disp('The final desired concentration has not been reached, moving to 3rd CSTR');
    p = ['The value of CA3 is: ',num2str(CA3)];
    disp(p);
end

For additional information, refer the following MathWorks documentation on “if, elseif, else”:

https://www.mathworks.com/help/matlab/ref/if.html