How can I solve those questions ?

how can I sovle those questions :

Q1: Use the least square methods to find the most suitable equation for fitting the following data:

I(min): 1.02 ,0.84 ,0.69 ,0.56 ,0.38 ,0.17

CA(Ibmole/ft)): 1.5 ,2.0 ,2.5 ,3.0 ,4.0, 6.0

Test the following equation to decide which one will fit with small error:

The error = Σ(CA - CAexp )^2

1. CA = CAo exp(-kl)

2. CA= CAo I^K

3. 1/CA= CAo+ I^K

Note: CA0 and K are the equation constants (slope and intercept depends on equation in the liner mode)

,..,.,..,...,...,..,....,....,......,......,.....,....,.....,.....,.....,....,.....,.....,

Q2:

a) Use Antoine Equations to fit the following data: Antoine Equation :

 In (p*)=A- B/C+T

T(C): 30 50 100 150 200 250

p(atm): 0.042 0.122 1.00 4.70 15.36 39.22

b) calculate the pressure at temperature of 400 K ?

that's it i hope you help me and thank you

Answer 1

[Matt J]

Useful commands: lsqcurvefit (if you have it), fminsearch (if you don't)

[m ksuu]

Thank you very much Mr.Matt J for you help appreciate that but I need some details..

Answer 2

[Star Strider]

The Antoine Equation is easy:

% % % Antoine Equation
% % % log10(p) = A - B/(C + T)
pm = @(b,T) 10.^(b(1) - b(2)./(b(3)+T));    % Objective Function

T = [30 50 100 150 200 250];
p = [0.042 0.122 1.00 4.70 15.36 39.22];

Cost = @(b) sum((p - pm(b,T)).^2);          % Sum-Of-Squares Cost Function
[b, fv] = fminsearch(Cost, [3 5 7]');

p400 = pm(b,400);                           % Get Pressure At T = 400°C

I took the base-10 antilog of the equation because the Wikipedia article on the Antoine equation describes it as being a base-10 log. You can keep it as a log if you like, but you will need to rewrite the equation and do the appropriate data transformation.

[m ksuu]

Thank you Thank you Mr. Star Strider you're life saver but can you post it in order and also question number one I need solution for it , hint anything you could help me with

[Star Strider]

My pleasure!

This should provide you with everything you need to answer Question #1. You just need to adapted the code.