1. Heat of Combustion – The heat produced when one mole of a substance is completely burnt in excess oxygen.
  2. Heat of Formation – The heat change when one mole of a compound in its standard phase is formed from each of its elements in their standard phases.
  3. Heat of Reaction – The heat change when the numbers of moles indicated in the balanced equation for the reaction reacts completely.
  4. Heat of Neutralization – The heat change when one mole of H+ ions from an acid reacts with one mole of OH- ions from a base.
  5. Hess’s Law of Heat Summation – The heat change for a reaction is the same whether the reaction takes place in one step or several steps.
  6. Law of Lavoisier and Laplace – Heat change for reverse reaction is equal but opposite in sign to forward reaction
  7. Exothermic – Gives out heat. Feels hot. ∆H is negative
  8. Endothermic – Takes in heat. Feels cold. ∆H is positive
  9. Atom – Smallest particle of matter that can exist by itself
  10. Matter – Anything that occupies space
  11. Element – Substance made up of one type of atom – cant be broken into anything simpler by chemical means
  12. Molecule – Smallest particle of substance that shows properties of that substance Group of atoms chemically joined
  13. Solution – Mixture of solute [solid] and solvent [liquid]. Cannot be separated by filtration.
  14. Mixture – Two or more substances not chemically joined. Composition can vary.
  15. Isotopes – Forms of element with different mass number due to different numbers of neutrons
  16. The Mole – 1 mole = 1 mole= RMM (relative molecular mass) in grams = Avogadro’s number (6*1023)= 22.4l of any gas at STP [ 273 K and 760mm of Hg ]
  17. Avogadro’s Law – 1 mole of any gas at STP occupies 22.4 L
  18. Kinetic Energy – = ½ mv2 [m = mass, v = velocity]
  19. Atomic Number – Number of protons in an atom. Determines what the element is.
  20. Mass number – Number of Protons + neutrons in an atom
  21. Relative Atomic Mass – 1. average of the mass numbers of the isotopes of the element. 2. as they occur naturally 3. taking their abundances into account4. expressed on a scale on which atoms of the carbon 12 isotope have a mass of exactly 12 units.
  22. Relative Molecular Mass – 1. The sum of the relative atomic masses of all the atoms in a molecule of the compound.2. The mass of one molecule of that compound compared with one twelfth of the mass of the carbon 12 isotope.3. Mass of one mole of a compound = Relative Molecular Mass in grams.
  23. Energy Level – The fixed energy value that an electron in an atom may have.
  24. Atomic Orbital – The region in space within which there is a high probability of finding an electron.
  25. Hund’s Rule of Maximum Multiplicity – When 2 or more orbitals of equal energy are available, the electrons occupy them singularly before filling them in pairs.
  26. Aufbau Principle – Electrons occupy the lowest available energy level.
  27. Pauli Exclusion Principle – No more than 2 electrons may occupy an orbital and they must have opposite spin.
  28. Heisenberg’s Uncertainty Principle – The more accurately we know the position of a particle the less accurately we know its velocity.
  29. First Ionisation Energy – The energy required to completely remove the most loosely bound electron from a neutral gaseous atom in its Ground State. [ X – e- = X+ ]
  30. Second Ionisation Energy – The energy required to completely remove the second most loosely bound electron from the ion X+ – e- = X2+
  31. Atomic Radius – Half the distance between 2 adjacent atoms of the same element joined by a single covalent bond
  32. Oxidation Number – The charge that an atom has or appears to have when electrons are distributed according to certain arbitrary rules.
  33. Electronegativity – The relative attraction that an atom in a molecule has for the shared pair of electrons in a covalent bond.
  34. Boyle’s Law – At constant temperature, the volume of a fixed mass of gas is inversely proportional to its pressure.
  35. Charles’s Law – At constant pressure, the volume of a fixed mass of gas is directly proportional to its temperature measured on the Kelvin scale.
  36. Equation of State [for an ideal gas] – PV = nRT [ n = number of moles, V=volume in m3; T = Kelvin; R = gas constant 8.31; p = pressure]
  37. Avogadro’s Law – Equal volumes of gases contain equal numbers of molecules, under the same conditions of temperature and pressure.
  38. EDTA – Ethylenediaminetetraacetic acid
  39. Acid – Arrhenius: a substance that dissociates in water to produce H+ ions.Bronsted-Lowry a proton [H+] donor.
  40. pH : -log10[H+] or -log10[H3O+] = 14 – pOH = -log10√(Ka * [H3O+])
  41. Base – Arrhenius: a substance that dissociates in water to produce OH- ions.Bronstead-Lowry:a proton [H+] acceptor.
  42. Amphoteric – Has both acid and basic properties at the same time. E.g. Aluminium, aluminium oxide
  43. pOH : -log10[OH-]
  44. Radioactivity – The spontaneous breaking up of unstable nuclei with the emission of one or more types of radiation.
  45. Half-life – The time taken for half of the nuclei in any given sample to decay.