Acids and Bases

Properties
1. Acids contains H+ ions
  1. Proton donor
  2. Have a pH of 1-6
  3. Acids turn blue litmus paper red
  4. The Universal indicator scale shows that acids are red, yellow or orange.
    1. Red is a strong acid
    2. methyl orange indicators- turns yellow with alkali and orange with acid
    3. Phenolphtahalien turns colourless in acids and pink in alkalis
  5. Strong acids contain mainly H+ ions whereas weak acids contain less
2. Bases/alkalis contain OH- ions
  1. Proton acceptors
  2. Have a pH of 8-14
  3. alkalii's turn red litmus paper blue
3. Water is neutral and has a pH of 7
Metal salts
1. are all alkaline
2. created by reacting a metal and an acid
  1. Hydrogen gas is produced as a by product
3. Can be made by titration, precipitation and neutralisation
  1. Titration: used to find the amount of acid needed to neutralise a known amount of alkali or vice versa
4. acids plus metal oxides or hydroxides makes a metal salt an water
5. acids plus metal carbonates make carbon dioxide, metal salt and water
6. naming salts
  1. nitric acid- makes nitrates
  2. hydrochloric acid makes chlorides
  3. sulphuric acid makes sulphates
Types of acids
1. Hydrochloric acid HCl is a strong acid
2. Sulphuric acid H2SO4 is a strong acid
3. ethanoic acid is a weak acid which is also called vinegar
  1. Infact all carboxylic acids are weak acids
4. nitric acid HNO3 iis a strong acid
Calculations
1. Concentration in moles/dm3 is the number of moles divided volume in dm3
Solubility rules
1. all nitrates are soluble
2. all chlorides are soluble except for silver and lead
3. all sodium, potassium and ammonium salts are soluble
Neutralisation
1. occurs when H+ ions and OH_ ion fully dissasociate
Where do we find them?
1. beestings
  1. can be neutralised with baking soda
2. ctric acids found in citrus fruits
3. Sulphur dioxide reacts with water in the clouds to make acid rain
4. use quicklime and slaked lime to neutralise acidic soil
Tests for cations and anions
1. ts for carbonates - add HCl, if CO2 is produced it will turn limewater milky
2. chloride, bromide and iodide ions: acidify with dilurte acid and add barium nitrate
  1. Chrloride: white ppt
  2. Bromide cream ppt
  3. Iodide: yellow ppt
3. Fe2+ and Fe 3+ ": add NaOH, grreen ppt for Fe2+ and Red/brown ppt for Fe3+
oxides
1. amphroteric oxides are act as both acids and bases
2. basic oxides are always metal oxides
Safety
1. strong acids and bases are corrosive

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Acids and Bases

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