chemical changes

• the metal reactivity series from most reactive to least:

  1. potassium
  2. sodium
  3. lithium
  4. calcium
  5. magnesium
  6. carbon
  7. zinc
  8. iron
  9. hydrogen
  10. copper
• what does OILRIG stand for?

  Oxidisation Is Loss Reduction Is Gain (of electrons)
• metals less reactive than carbon can be extracted from their oxides by reduction with carbon
• the reactivity of a metal is related to its tendency to forming positive ions
• a more reactive metal can displace a less reactive one from a compound, in a displacement reaction
• acids react with some metals to produce hydrogen and a salt: this is called a redox reaction, where one element is oxidised and another is reduced
• acids are neutralised by alkalines (soluble metal hydroxides) and bases (insoluble metal hydroxides and metal oxides) to produce salts and water.
• acids are neutralised by metal carbonates to produce a salt, water and carbon dioxide.
• acids used for salt production often are:

  • hydrochloric acid (HCl)
  • nitric acid (HNO3)
  • sulfuric acid (H2SO4)
• acids produce H+ ions in aqueous solutions
• alkalies produce OH+ ions in aqueous solution
• the Ph scale is from 0-14, anything below 7 is acidic, 7 is neutral and anything above 7 is alkali.
• what is a strong acid?

  an acid completely ionised in aqueous solution
• what is a weak acid?

  partially ionisied in aqueous solution
• as pH decreases by one unit, the H+ concentration of the solution increases by a factor of 10
• 1dm^3 = 1000cm^3
• when balancing neutralisation equation, the positive ion from the alkali/base/carbonate and the negative ion from the acid must add up to 0
• metal + acid > salt + hydrogen

  metal oxide + acid > salt + water

  metal hydroxide + acid > salt + water

  metal carbonate + acid > salt + water + carbon dioxide