And our t final minus t initial so 31 -23 and we get 640 joules. But this corresponds to 00:25 moles of HCL and 00:25 moles of soyu hydroxide. We want to find what corresponds to 1 mol of each. So we basically have to multiply this guy by four, or we could divide this guy by 00:25. We get the same answer. So 640 joules divided by zero point 250 mole gets you 2560 joules per mole.