Welcome, kaizer64! My two cents:
O, should produce the same heat per mole independently of the nature of the acid and base at reasonable concentration.
While you neutralize the weak acid with NaOH, the acid ionizes more and more, and the heat amount produced by H+
depends only on the amount of NaOH used. It doesn't relate with the amount of H+
present before the neutralization.
Much of the ionisation of the acid happens during the measure of heat. It should absorb heat.
NaOH shouldn't be too concentrated as its dilution produces significant heat. The heat of dilution of OH-
doesn't matter because it gets neutralized, but the heat of dilution of Na+