There are a few problems with your code as written:
First, you are using curly braces instead of using the while/end or if/end syntax that you are supposed to use in MATLAB. You also don't need parentheses for your if and while statement and I think you want a double equals sign for your equals comparison. It should look like this:
if time == 11
break
end
Your while loop should be:
while count < 11
%insert the rest of your code here
end
Finally, you initialize t=0 but I think you meant time=0 because you use the variable 'time' later.
All in all, your code should look like the following:
time = 0;
Cai = 4;
Cbi = 1;
P = .15;
A = .85;
N1 = Cai;
N2 = Cbi;
J3 = 0;
count = 1;
while count < 11
J3 = N1/t;
Ca0 = -(J3/P)+Cai;
count = count+1;
time = time +1;
plot(Ca0, time);
xlabel('Time (sec)');
ylabel('Ca0 (moles)');
if time == 11
break
end
end
