Observations of acid and base reactions

• Complete this formula

  Acid + alkali = …

  Acid + alkali = salt + water
• Complete this formula

  Acid + metal oxide = ...

  Acid + metal oxide = salt + water
• Complete this formula

  Acid + metal carbonate = ...

  Acid + metal carbonate = salt + water + CO2
• Describe three observations we can make to identify that neutralisation is a chemical reaction, and how we can make these observations

  Energy change – measured by a change in temperature

  pH change – measured using a pH probe (or chemical indicator)

  Gas is evolved (collected in an inverted test tube full of water)
• Describe the test for oxygen gas, including the result for a positive test

  insert a glowing splint into the tube. If the splint relights, oxygen is present
• Describe the test for hydrogen gas, including the result for a positive test

  Insert a lit splint into the tube. If a squeaky pop / explosion is heard, hydrogen is present
• Describe the test for carbon dioxide gas, including the result for a positive test

  Bubble the gas through limewater. If a cloudy white precipitate forms, carbon dioxide is present.