FA0 = 0.867; // mol/s
X1 = 0.5;
X2 = 0.8;
rA2 = -(1/800);
X = [0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8]';
p = [189 192 200 222 250 303 400 556 800];//1/-rA = 800//dm^3.s/mols