AQA A LEVEL CHEMISTRY EXAM 2024

AQA A LEVEL CHEMISTRY EXAM 2024 mean bond enthalpy - ANSWER-The energy required to break a covalent bond into gaseous atoms averaged over different molecules Bonds broken - bonds made activation energy - ANSWER-The minimum amount of energy needed to start a chemical reaction catalyst - ANSWER-A substance that increases the rate of a chemical reaction without being changed by providing an alternative reaction pathway by lowering activation energy Le Chatelier's principle - ANSWER-When a system in dynamic equilibrium is subjected to change, the position of equilibrium will shift to oppose the change. oxidising agents - ANSWER-electron acceptors reducing agents - ANSWER-electron donors Enthalpy of formation - ANSWER-Enthalpy change when one mole of a compound is formed from its constituent elements under standard conditions in their standard states Enthalpy of atomization - ANSWER-The energy required to produce one mole of gaseous atoms from an element in its standard state Electron affinity - ANSWER-the enthaply change when one mole of gaseous atoms forms one mole of -1 ions Lattice enthalpy of formation - ANSWER-Enthalpy change when one mole of a solid ionic compound is formed from its constituent ions in the gas phase Relative atomic mass - ANSWER-The average mass of an atom of an element, relative to 1/12th of the mass of an atom of Carbon-12 Relative molecular mass - ANSWER-Average mass of a molecule compared to 1/12th of the mass of a carbon-12 atom