enthalpy changes

Question 1

standard enthalpy change of a reaction

Answer 1

enthalpy change when a reaction occurs in the molar quantities as shown in the chemical equation, under standard conditions

Question 2

standard enthalpy change of formation

Answer 2

enthalpy change when one mole of a compound is formed from its elements in their standard states, under standard conditions

Question 3

standard enthalpy change of combustion

Answer 3

enthalpy change when one mole of a substance is completely burnt in oxygen, under standard conditions

Question 4

standard enthalpy of neutralisation

Answer 4

measured from the energy given out when acids react with alkalis in aqueous solution to form a salt and one mole of water