Gases

• % of nitrogen

  78%
• % of oxygen 


  21%
• % of argon 


  1%
• % carbon dioxide

  0.04%
• sodium + oxygen 


  bright yellow flame
• magnesium + oxygen 


  bright white light

  white powder formed
• sulfur + oxygen 


  blue flame
• carbon + oxygen 


  yellow/orange flame
• examples of metal oxides

  bases

  sodium oxide + magnesium oxide are alkalis

  aluminum oxide is insoluble
• examples of non-metal oxides

  silicon dioxide is insoluble

  carbon dioxide + sulfur dioxide are acidic
• thermal decomposition 


  breaking up a compound by heating it
• precautions

  suck back- delivery tube must be removed from limewater before heating ends

  burns - take care with hot equipment
• when metal carbonates are heated.. 


  they break down to form the metal oxide and carbon dioxide
• general word equation for thermal decomposition

  metal carbonate —> metal oxide + carbon dioxide
• metals lower down in the reactivity series will..

  decompose easily and quicker with heat
• metals higher up in the reactivity series.. 


  have stable carbonates and will decompose slower as a lot of energy is needed for the carbonate to decompose
• upward delivery is used for gases..


  less dense than air
• downward delivery is used for gases..


  more dense than air
• displacement of water is used for gases..

  that are insoluble in water
• a gas syringe is used for collecting…


  any gas
• test for hydrogen 


  lit splint held over test tube causes squeaky pop
• test for oxygen 


  a glowing splint will relight in a test tube
• test for carbon dioxide 


  limewater turns cloudy
• test for chlorine 


  damp blue litmus paper turns red and then bleaches white
• test for ammonia 


  damp red litmus paper turns blue