exothermic and endothermic

• Exothermic reactions are chemical reactions that release energy to their surroundings.
• When exothermic reactions take place, the temperature of the surroundings increases as a result of the release of energy
• Examples of exothermic reactions are combustion, neutralisation of an acids and bases, and the freezing of water.
• Handwarmers and self heating camping meals make use of exothermic chemical 
• Endothermic reactions are chemical reactions that absorb energy from their surroundings
• As energy is being absorbed from the surroundings in endothermic reactions, the temperature of the surroundings decreases
• Examples of endothermic reactions include thermal decomposition reactions. 
• One practical use of endothermic reactions is in sports injury packs. 
• exothermic

  
• endothermic

  
• Electrochemical cells make use of the fact that chemical reaction generate electricity.
• Fuel Cells are special types of electrochemical cell that require a constant supply of fuel to operate.
• hydrogen oxygen fuel cells

  2H2​+O2​→2H2​O
• Reduction: The gain of electrons
• Oxidation: The loss of electrons 
• Redox reactions are ones that involve the transfer of electrons between the reactants
•  metals tend to appear in the Earth’s crust as compounds known as ores
• To extract pure metals from their oxide ores, they must be reduced
• Please stop like calling me a careless zebra instead try learning how copper saves gold

  potassium sodium lithium calcium magnesium aluminium zinc iron tinc lead hydrogen coppe silver god
• • Acids: Substances that will produce hydrogen (H+)(H+) ions in aqueous solutions.
• • Bases: Substances that will produce hydroxide (OH−)(OH−) ions in aqueous solutions.
• The more H+H+ ions that a substance produces in solution, the more acidic the substance. The more OH−OH− ions a substance produces, the more basic (or alkaline) it is. 
• displacement reaction?


  more reactive element is replaced by a less reactive element
• OIL RIG


  oxidation is loss of electrons reduction is gain
• Cats have paws


  cations are +
• please stop like - potassium, sodium, lithium with water


  fizzes
• P S L - ACID


  EXPLODES
• CMAZI- WATER


  REACTS SLOWLY
• CMAZI- ACID


  FIZZES
• TLH- WATER


  NO REACTION
• TLH- METAL


  REACTS SLOWLY WITH WARM WATER
• 3 xamples of strong acids

  HCL, sulfuric, nitric
• 3 examples of weak acids

  ethanoic carbonic citric
• dilute acids


  lots of ions
• when dissolved in water acids release

  H+ iona
• when dissolved in water alkaline releases


  OH- ions
• chromium iii oxide


  green
• cobalt ii sulfate


  red
• negative ions are attracted to + electrode