test for gases

• Test for oxygen


  Use a glowing splint. glowing splint relights in the presence of oxygen.
• Test for hydrogen


  Use a lighted splint. lighted splint will distinguish with a pop sound in the presence of hydrogen.
• Test for carbon dioxide

  Bubble gas into limewater. White precipitate will form in the limewater when carbon dioxide is present.
• Test for ammonia


  Use a damp red litmus paper. Damp litmus paper turns blue in the presence of ammonia.
• A physical change happens when no new substances are formed.
• A chemical change is when new substances in the form of elements/compounds are formed
• acid reacts with an alkali to form salt and water.
• an acid reacts with a metal to form salt and hydrogen gas
• an acid reacts with a metal carbonate to form salt, water, and carbon dioxide gas.
• Combustion, oxidation reaction: must have oxygen as reactant!
• Combustion


  Substance reacts with oxygen to form one or more new substances. Heat is given off.
• Oxidation


  substance gains oxygen
• Thermal decomposition


  one substance breaks down into two or more simpler substances upon heating
• Electrolysis


  chemical reaction brought about by passing an electric current through an electrolyte.