A LEVEL CHEMISTRY WITH VERIFIED QUESTIONS AND ANSWERS

A LEVEL CHEMISTRY WITH VERIFIED QUESTIONS AND ANSWERS

Weak acid - an acid that is only slightly ionised/dissociated in aqueous solution

Oxidation - loss of electrons

Reduction - gain of electrons

Ionic bonding - The electrostatic attraction between oppositely charged ions

Covalent bonds - sharing of a pair of electrons

Electronegativity - the ability of an atom to attract the electrons in a covalent bond

Relative atomic mass - The weighted mean mass of an atom of an element compared with one-twelfth of the mass of an atom of carbon-12.

Relative isotopic mass - The mass of an atom of an isotope compared with one-twelfth of the mass of an atom of carbon-12.

empirical formula - The simplest whole number ratio of atoms of each element present in a compound

molecular formula - A chemical formula that shows the number and kinds of atoms in a molecule, but not the arrangement of the atoms.

anhydrous - without water

Hydrated - A crystalline compound containing water molecules

Water of crystallisation - Water molecules that are bonded into a crystalline structure of a compound

strong acid - an acid that ionises/dissociates completely in aqueous solution

1st ionisation energy - ANSWERenergy change when one mole of electrons is removed from one mole of gaseous atoms

Metallic bonding - ANSWERthe chemical bonding that results from the attraction between metal ions and the surrounding delocalised electrons

Disproportionation - ANSWERThe oxidation and reduction of the same element in a redox reaction

Activation energy - ANSWERthe minimum amount of energy required to start a chemical reaction

standard enthalpy of formation - ANSWERenthalpy change if 1 mole of compound in standard state were formed directly from its elements