chemistry unit 1 summary

HideShow resource information
  • Created by: Asal
  • Created on: 22-12-12 22:22
View mindmap
  • Chemistry
    • first ionisation energy
      • The energy required to remove an electron from each atom in one mole of gaseous atoms
      • Mg (g)  -> Mg+ + e-
    • van der waals' forces
      • uneven distribution of electrons produces an instantaneous dipole the dipole induces dipoles in neighbouring molecules, dipoles attract one another
    • bond angles
      • electron pairs repel lone pairs repel more than bonded pairs
      • 2 bonds linear 3 bonds trigonal 4 bonds tetrahedral 6 bonds octahedral
      • - 2.5 degrees for each lone pair
      • silicon dioxide bent one lone pair 118 degrees water bent two lone pairs 104.5 degrees
    • intermolecular forces- permanent dipole-dipole interactions van der waals' forces
    • hydrogen bonds ice is less dense than water ice forms an open lattice of hydrogen bonds
      • h bonds hold water molecules together tightly at the surface means water has a high surface tension
    • mole- avogadro constant when a substance has as many particles as there are carbon atoms in 12 grams of carbon 12.
    • thermal decomposition- using heat to break a compound into at least two substances
    • Ag+ (aq) + Cl- (aq) -> AgCl
      • Add silver nitrate- precipitation reaction precipitate forms, chloride ions present white precipitate forms iodide ions present yellow precipitate forms bromide ions present cream  precipitate forms
    • disproportionation reaction- when the same element is both oxidised and reduced
      • redox reaction- a reaction in which both oxidation and reduction takes place
    • electronegativity the ability of an atom to attract the bonded pair of electrons in a covalent bond
      • a  non-polar molecule is symmetrical so all polar bonds cancel each other out
    • metallic bonding- electrostatic attraction between metal ions and delocalised electrons
    • ionic bonding- electrostatic attraction between oppositely charged ions
    • covalent bonding the sharing of a pair of electrons
      • dative covalent bonding- the two electrons in a covalent bond are provided by one atom only
    • Oxidation numbers hydrogen 1+ oxygen 2- chlorine 1- ion  charge on ion unbonded element 0
    • salt- when the h+ ion on an acid is replaced by a metal ion or an NH4+ ion
      • acid proton donor
      • base proton acceptor
    • I2+ Cl2-> 2Cl- + I2 displacement reaction
      • mole n=m/M
        • gas volume  v=n x 24 in dm3 or 24000 in cm3
        • concentration n=c x v in dm3 or v/1000 in cm3
          • in titration c= n x 1000/ v
    • hydrated- with water
      • anhydrous without water
      • water of crystallisation the water that forms an important part of the crystalline structure
  • first ionisation energy
    • The energy required to remove an electron from each atom in one mole of gaseous atoms
    • Mg (g)  -> Mg+ + e-
  • van der waals' forces
    • uneven distribution of electrons produces an instantaneous dipole the dipole induces dipoles in neighbouring molecules, dipoles attract one another
  • hydrogen bonds ice is less dense than water ice forms an open lattice of hydrogen bonds
    • h bonds hold water molecules together tightly at the surface means water has a high surface tension
  • a  non-polar molecule is symmetrical so all polar bonds cancel each other out
  • dative covalent bonding- the two electrons in a covalent bond are provided by one atom only

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all resources »