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CHEMICAL CHANGES (anna) - Coggle Diagram

- - - - alkalis have a pH value less than 7
        
        alkalis are corrosive
        
        alkalis can conduct electricity
        
        alkalis react with acid to produce salt and water. this reaction is called neutralisation
  - - - they neutralise excess acid in soil
- - - - do not show how strong or weak an acid or an alkali is
  - - - only indicate whether a solution is an acid or alkali but also can tell us how strong or weak an acid or alkali is.
- - - - nitric acid
        
        HNO3
      - HCI
  - - - ethanoic acid
        
        lactic acid
        
        tartaric acid
        
        apple
        
        dairy products
        
        vinegar
      - in citrus fruits
  - - - acids turn blue litmus paper red
        
        acids have a pH value less than 7
        
        acids are corrosive
        
        acids can conduct electricity
        
        acids react with metals, carbonates, and bases/alkalis
- - - - ethanoic acid
        
        citric acid
        
        nitric acid
        
        Used to make explosives, plastics and medicinal drugs
        
        Used as preservative and flavouring in foods
        
        Used in vinegar to preserve food
      - Removal of rust from iron and steel objects Used in leather processin
        
        clean metal oxide formed on
        the surface of an alloy
    - - Making fertilisers
- - - - if x is acid y must be carbonate
        
        e.g Nitric acid + sodium carbonate sodium nitrate + water + carbon dioxide
        
        Limewater (or calcium hydroxide) is used to test for the carbon dioxide produced from the reaction
        
        It is a chemical test as the presence of carbon dioxide will have the following observation.
        
        Limewater turns cloudy/chalky/milk
  - - - e.g Hydrochloric acid + calcium calcium chloride + hydrogen
      - acid + metal → salt + hydrogen
      - A lighted splint is used to test for hydrogen gas produced from a reaction(It releases a gas when a metal is dropped in it.)
      - The presence of hydrogen will have the following results:
        
        – A ‘pop’ sound is produced.
        
        – The lighted splint extinguishes
      - there are calcium/metal strips
  - - - acid + base/alkali → salt + water
      - e.g Hydrochloric acid + zinc oxide zinc chloride + water