Calculations

• Group 1 metals react with water to form group 1 metal hydroxide and hydrogen gas
• Lithium:

  • Least reactive
  • Not easy to cut
  • Silver inside, grey outside
  • Popped near a lit splint
• Sodium:

  • Between the most and least reactive
  • White outside, inside tarnishes quickly from silver
  • Fast fizzing
  • Movement
  • Sparks
• Potassium:

  • Most reactive
  • Greyish silver outside, white inside but darkens
  • Fast fizzing
  • Fast movement
  • Produces sparks and a flame
• Equations:

  • Metal + acid → salt + hydrogen
  • Acid + base → salt + water
• Displacement reactions:

  • When an element is more reactive than another and displaces it in a reaction
  • E.g. sodium + iron oxide → sodium oxide + iron
• Acids:

  • Hydrochloric acid → HCl → Forms chlorides
  • Sulfuric acid → HSO → Forms sulphates
  • Nitric acid → HNO → Forms nitrates
• Order of reactivity:

  • Potassium
  • Sodium
  • Lithium
  • Calcium
  • Magnesium
  • Aluminium
  • Zinc
  • Iron
  • Tin
  • Lead
  • Copper
  • Silver
  • Gold
• Extracting metals:

  • Metal ore: a rock with enough metal to economically extract
  • Less reactive than hydrogen but can be reduced using hydrogen
  • Metal oxide + hydrogen → metal + water
  • E.g. Copper oxide + carbon → copper + carbon dioxide
• Salts:

  • Formed when the hydrogen in an acid is replaced by a metal or ammonium ions
  • Can be made by reacting a metal with an acid or a metal oxide/carbonate with an acid
• Alkalis and bases:

  • Bases do not always dissolve in water, alkalis do
  • Bases can be insoluble, alkalis react similarly when reacted with an acid
  • Bases tend to be metal oxides
• Required practical:

  • Use a 100ml beaker and 40ml sulfuric acid
  • Set up a tripod, gauze, and heatproof mat, then heat the sulfuric acid
  • Add excess copper oxide
  • Filter out excess copper oxide
  • Leave in the window to evaporate and form crystals
  • Heating is required to ensure no other liquids are present and to speed up the reaction
  • Add excess copper oxide to fully neutralize the reaction
  • Filtering removes excess copper oxide as it is insoluble
  • Leave by the window to slow evaporation for larger crystals
• Formula of a compound:

  • Uses chemical symbols and numbers to show the ratio of atoms of each element present
  • Calculate the charge for each type of ion
  • Balance ions so positive and negative charges are equal
  • Use the ratio to write down the formula of the ionic compound
  • E.g. Al → Br
  • 1 electron for each bromine atom
  • AlBr
• Acids and alkalis:

  • Acids release ions into solution when added to water
  • Alkalis dissolve in water to form hydroxide ions and release ions into a solution when added to water
• Weak and strong acids:

  • Strong acids: Hydrochloric acid, Sulfuric acid, Nitric acid
  • Weak acids: Ethanoic acid, Citric acid, Carbonic acid
  • Strong acids are fully ionized, weak acids are only partly ionized
  • A 0.1m solution of HCl has a pH of 1