Reactions of acids

Some general observations can be made during acid reactions:

  • if a gas is produced, the observations is ‘bubbles’.
  • if a solid such as a solid metal, base or carbonate reacts with the acid then the observation is ‘solid disappears and a solution is produced’.
  • most acid reactions are exothermic – the observation is ‘heat released’. Exceptions – copper(II) oxide and sodium hydrogencarbonate with acid.

It is useful to know the colour of some compounds commonly reacted with acids to work out if a colour change has occurred.

SubstanceColour
copper(II) oxideblack solid
copper(II) carbonategreen solid
hydrated copper(II) sulfateblue crystals
copper(II) salts in solutionblue solution
group 1, group 2, aluminium and zinc compoundswhite solids – if they dissolve in water they give colourless solutions

Prescribed Practical C1 - Investigate the reaction of acids, including temperature changes that occur