A level Chemistry - Paper 1 QUESTIONS AND ANSWERS

Enthalpy of formation - Enthalpy change when one mole of a substance is formed from its constituent elements with all substances in their standard states Enthalpy of combustion - Enthalpy change when one mole of a substance undergoes complete combustion in oxygen with all substances in their standard states 1st Ionisation enthalpy - Enthalpy change when one mole of gaseous atoms loses one electron per atom to form one mole of gaseous 1+ ions 2nd Ionisation enthalpy - Enthalpy change when one mole of gaseous 1+ ions loses one electron per ion to form one mole of gaseous 2+ ions 1st electron affinity - Enthalpy change when one mole of gaseous atoms gains one electron per atom to form one mole of gaseous 1- ions 2nd electron affinity - Enthalpy change when one mole of gaseous 1- ions gains one electron per ion to form one mole of gaseous 2- ions Enthalpy of atomisation - Enthalpy change when one mole of gaseous atoms is produced from an element in its standard state Enthalpy of hydration - Enthalpy change when one mole of gaseous ions becomes hydrated (dissolved in water)