AQA A LEVEL Chemistry Test with Verified Solution 2024/2025 Graded A+

AQA A LEVEL Chemistry Test with Verified Solution 2024/2025 Graded A+ Relative atomic mass - - 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 - - Average mass of a molecule compared to 1/12th of the mass of a carbon-12 atom The Avogradro constant - - the number of particles in a mole ideal gas equation - - pV = nRT empirical formula - - the simplest whole number ratio of atoms of each element in a compound percentage atom economy - - (Mass of desired product/total mass of reactants) x 100 ionic bonding - - the electrostatic attraction between oppositely charged ions in a lattice covalent bond - - a shared pair of electrons between non-metal elements co-ordinate bond - - a shared pair of electrons where both electrons are supplied by one atom repulsion in shapes of molecules - - Lone pair-lone pair > lone pair-bonding pair > bonding pair- bonding pair electronegativity - - the power of an atom to attract the pair of electrons in a covalent bond hess' law - - Total enthalpy change for a reaction is independent of the route chosen mean bond enthalpy - - The energy required to break a covalent bond into gaseous atoms averaged over different molecules Bonds broken - bonds made activation energy - - The minimum amount of energy needed to start a chemical reaction catalyst - - 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 - - When a system in dynamic equilibrium is subjected to change, the position of equilibrium will shift to oppose the change. oxidising agents - - electron acceptors reducing agents - - electron donors Enthalpy of formation - - Enthalpy change when one mole of a compound is formed from its constituent elements under standard conditions in their standard states Enthalpy of atomization - - The energy require