Question

Find the quantity of heat produced when 100ml of 0.1N HCL is completely neutralised with NAOH solution

Answer 1

Do you have any other information? You need, at least, the heat of neutralization for H^+ + OH^- ==> H2O. I don't remember but think it's about 55 kJ/mol.
HCl + NaOH ==> NaCl + H2O
You have mols HCl = M x L = 0.1 x 0.1 = 0.01 mols.
So approx 55 kJ/mol x 0.01 mol = approx 0.55 kJ. You can look up that number and go from there.