$word_{count}$: 190

Two types of calorimeters: (1) Bomb calorimeter: rigid steel vessel, constant volume. Measures $delta_U$ (= qv). q = $C_{calorimeter}$ x $delta_T$. To find $delta_H$: $delta_H$ = $delta_U$ + $delta_{ngas}$*RT. Used for combustion reactions. (2) Coffee-cup calorimeter: open container, constant pressure. Measures $delta_H$ (= qp) directly. q = m x c x $delta_T$, where c = 4.184 $\frac{J}{g.K}$ for water. Common in acid-base neutralisation experiments. For neutralisation: $delta_H$ = -q/moles of limiting reagent (negative sign if temperature rises, indicating exothermic). Assumptions: no heat loss to surroundings, specific heat of solution equals that of water, density of dilute solution equals 1 g/mL. Calibration of bomb calorimeter uses benzoic acid (known $delta_{Hc}$). Key conversion: 1 cal = 4.184 J. When water is a product: check whether it forms as liquid (standard state) or gas — this affects $delta_H$ by 44 kJ/mol per mole of water.