Metals and reactivity

• What two things make iron rust?

  Water and oxygen
• what is galvanised iron?


  Using a coating of zinc around iron to offer protection

  -> zinc will corrode before iron as it is more reactive
• what can accelerate rusting?

  salt solution (sodium chloride)
• order of reactivity series

  potassium

  sodium

  lithium

  calcium

  magnesium

  aluminium

  zinc

  iron

  copper

  silver

  gold
• hydrogen ion

  H+
• What state do ionic compounds have to be to conduct electricity and why?

  liquid or dissolved in water

  -can only conduct electricity when charged particles can move

  -In solid the particles are fixed

  -When melted, the ions are free to move allowing them to conduct electricity
• What is the colour chance if copper sulfate becomes hydrated?

  White to blue
• sulfate ion

  SO4 2-
• Name all diatomic elements (7)

  hydrogen

  nitrogen

  oxygen

  fluorine

  chlorine

  bromine

  iodine
• ammonia


  NH3
• Hydrogen chloride


  HCl
• hydrochloric acid

  HCI
• methods to prevent rusting

  sacrificial protection

  -galvanising

  Barrier protection

  -painting

  -greasing
• percentage yield =

  actual yield/theoretical yield *100
• reasons we might not make as much product:

  • Reactants might not all react
  • side reactions (other than one we're expecting)
  • lose some product during process -> e.g. left in filter paper
• ammonium


  NH4+
• Explain why simple molecules have low melting points

  • They have weak intermolecular forces (1)
  • that require little energy to overcome (1)
• Why does iodine have a higher melting point than bromine

  Iodine is a larger molecule

  Therefore its intermolecular forces are stronger

  More energy required to overcome the forces
• copper (I) ion


  Cu+
• Difference between actual yield and theoretical yield


  Theoretical- yield we would expect based on calculations

  Actual- Actual amount of product when carrying out reaction
• What is ionic bonding


  The electrostatic attraction between oppositely charged ions formed by the transfer of electrons from metals to non-metals
• phosphate ion


  PO4 3-
• rf value


  Rf = distance travelled by solute/ distance travelled by solvent
• concentration formula

  concentration = mass/volume ( if volume cm3 divide by 1000 to get dm3)
• mole formula


  moles = mass / mr
• Iron (II) ion


  Fe2+
• Iron (III)


  Fe 3+
• lead (II)


  Pb2+
• zinc ion


  Zn 2+
• Copper (II)


  Cu2+
• Silver


  Ag+
• Hydroxide


  OH-
• Hydrogen carbonate


  HCO3 -
• Nitric acid


  HNO3
• allotropes


  Different structural forms of the same element in the same physical state
• nitrate ion


  NO3 -
• formula for rust

  Fe2O3 * H2O

  hydrated Iron(III) oxide
• What do multiple ions form?

  regular lattice structure
• Why are ions attracted to other ions with opposite charge?

  due to electrostatic forces- the attraction is known as ionic bonds and are extremely strong
• sulfuric acid

  H2SO4