Acids and alkalis

• What colour does red litmus turn?

  Acid- remains red

  Alkali- blue

  Neutral- remains red
• What colour does blue litmus turn?

  Acid- turns red

  Alkali- remains blue

  Neutral- remains blue
• what colour does universal indicator turn?

  Strong acid- red

  Slightly strong acid-orange

  Weak acid- yellow

  Strong alkali- purple

  Weak alkali- blue

  Neutral- remains geeen
• how Do you find pH more accurately and why?

  pH sensor as it provides a numerical value
• Hydrochloric acid, sulphuric acid and nitric acid are all…..

  Colourless liquids
• What’s the formula for sulphuric acid?

  H2SO4
• What’s the formula for nitric acid?

  HNO3
• What can an alkali also be described as?

  A substance that dissolves in water producing hydroxide ions
• What’s the ionic equation for neutralisation?

  H+(aq) + OH-(aq) —-> H2O(l)
• Sulphuric acid salts- sulphates

  hydrochloric Acid salts- chlorides

  nitric acid salts- nitrates
• Alkalis are also known as bases as they dissolve in water. Copper oxide is not an alkali as it doesn’t dissolve in water
• Hydrochloric acid ionising

  HCl(aq) —> H+(aq) + Cl-(aq)
• Copper oxide reacts with colourless dilute sulphuric acid to produce copper sulphate.

  stage 1

  •add 20cm^3 of the 0.5 m sulfuric acid to the 100cm^3 beaker.

  •heat carefully until nearly boiling

  •add small portions of copper oxide.

  •stir gently

  •when all copper oxide is added continue to heat.

  stage 2

  •allow to cool, gently swirl contents to mix

  •pour into filter paper,allow to filter through

  •clear blue solution should collect in flask

  •evaporate solution to leave blue copper sulphate crystals
• Acid + metal —> salt + hydrogen
• Acid + alkali —> salt + water
• Acid + metal carbonate —> salt + water + carbon dioxide
• Copper oxide— black

  copper carbonate- green

  hydrated copper sulphate-blue

  anhydrous copper sulphate- white

  all gp1 and gp2 and aluminium compounds- white