chemistry

• NITRITE


  NO2 -
• NITRATE


  NO3 -
• SILFITE


  SO3 2-
• SULFATE


  SO4 2-
• HYDROXIDE


  OH-
• PHOSPHATE


  PO4 3-
• CARBONATE


  CO3 2-
• CHLORATE


  CLO3 -
• ACETATE


  C2H3O2 -
• CHLORITE


  CLO2 -
• CYANIDE


  CN-
• BICARBONATE


  HCO3 -
• AMMONIUM


  NH4 +
• first ionisation energy


  The energy needed to remove 1 electron from each atom in 1 mole of gaseous atoms.
• metallic bonding


  the electrostatic force of attraction between the positive metal ions and the delocalised electrons
• rate of reaction

  the change in concentration of a substance in unit time.
• activation energy


  the minimum energy which particles need to collide to start a reaction.
• standard conditions

  100kPa, 298K, 1 moldm-3
• enthalpy change of reaction

  The enthalpy change when the number of moles of reactants as specified in the balanced equation react together.
• enthalpy change of formation


  the enthalpy change when 1 mole of a compound is formed from its elements in their standard states under standard conditions.
• enthalpy change of combustion

  the enthalpy change when one mole of a substance is combusted completely in oxygen under standard conditions.
• enthalpy change of neutralisation

  The enthalpy change when solutions of an acid and an alkali react together under standard conditions to produce 1 mole of water.
• Relative isotopic mass

  The mass of an atom of an isotope compared with one-twelfth of the mass of an atom of carbon-12.
• 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 molecular mass

  The average mass of a molecule compared to one twelfth of the mass of one atom of carbon-12.
• the mole


  the amount of a substance that contains as many particles as there are atoms in exactly 12 g of carbon-12
• molar mass


  the mass in grams of one mole of a substance
• empirical formula


  The simplest whole number ratio of atoms of each element in a compound.
• Molecular formula


  The actual number of atoms of each element in a molecule.
• ionic bonding


  The electrostatic force attraction between oppositely charged ions formed by electron transfer.
• covalent bonding

  the strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms.
• dative covalent bond (co-ordinate)


  formed when the shared pair of electrons in the covalent bond comes from only one of the bonding atoms.
• electronegativity


  the relative tendency of an atom in a covalent bond in a molecule to attract electrons in a covalent bond to itself.
• disproportionation


  a reaction where an element is simultaneously oxidised and reduced.
• activation energy


  the minimum energy needed for particles to collide to start a reaction.
• catalysts

  increase reaction rates without getting used up by providing an alternative route or mechanism with a lower activation energy so more molecules have energy above activation energy.
• hydrocarbon


  A compound containing hydrogen and carbon only.
• saturated

  contain single carbon-carbon bonds only
• unsaturated

  presence of double carbon-carbon bonds
• general formula


  algebraic formula for a homologous series e.g. CnH2n