for loop store building vector

I want this code to create a vector of pH as it iterates. i.e. pH will keep building with each iteration. The first parts is just calculations to get pH

% Initial conditions

Vinit = 0.1;

MCH3CO2H = 0.5;

pKa = 4.756;

Ka = 10^-pKa;

pKb = -log10(1e-14/Ka);

Kw = 1*10^-14;

Kb = Kw/Ka;

% Initial equilibrium concentrations

CH = max(roots([1 Ka -MCH3CO2H*Ka]));

% Initial number of moles

NCH = CH * Vinit;

NCH3CO2H = MCH3CO2H * Vinit;

% Initial pH

pHinitial = -log10(CH);

% Loop through different volumes

dV = 1e-5;

MNaOH = 0.1;

for k = dV:dV:1

      % Still before equivalence point
      if k < 0.49999999
          aCH3CO2H = NCH3CO2H - (MNaOH * k);
          CCH3CO2H = aCH3CO2H / (Vinit + k);
          NCH3CO2 = MNaOH * k;
          CCH3CO2 = NCH3CO2 / (Vinit + k);
          pH = pKa + log10(CCH3CO2 / CCH3CO2H);

      else
          bCH3CO2H = (MNaOH * k) - NCH3CO2H;
          CCH3CO2H = bCH3CO2H / (Vinit + k);
          CCH3CO2 = CCH3CO2H.^2 / (Kb);
          pH = 14 - (pKb + log10(CCH3CO2H / CCH3CO2));

      end

end

Answer 1

[Walter Roberson]

Before the loop,

J = 0;

First statement inside the loop:

J = J + 1;

Then in the if/else portion, instead of assigning to pH, assign to pH(J)

Note: your code would be much more efficient if vectorized.