Exothermic and Endothermic Reactions (Leaving Cert Chemistry): Flashcards

Increases

Negative ($\Delta H < 0$)

Combustion of hydrocarbons, neutralisation

Decreases

Positive ($\Delta H > 0$)

Thermal decomposition, photosynthesis

Heat released when 1 mole completely burned in excess $O_2$

Bomb calorimeter

Energy to break 1 mole of a covalent bond in gas

412 kJ/mol

Energy cannot be created or destroyed, only transferred or transformed

Total enthalpy change same regardless of pathway

Enthalpy change when 1 mole formed from elements in std states

Calorific value of fuels or food

Energy released when 1 kg of fuel is burned