WATER

• WHAT CAN WATER ACT AS?

  an acid and a base
• WATER ACTING AS AN ACID?

  H2O + NH3 -> OH- + NH4+
• WATER ACTING AS A BASE?

  HCl + H2O -> H3O+ + Cl-
• WHAT IS H3O+ CALLED?

  oxonium/ hydronium/ hydroxonium ion
• RULES ABOUT PROTONS?

  • H+ never found isolated
  • always found as H3O+ ions
  • no electrons of its own so must bond to a lone pair
• WHAT TYPE OF ACID OR BASE IS WATER?

  amphoteric (both)
• IONISATION OF WATER?

  slightly ionised
• EQUATIONS OF IONISATION OF WATER?

  H2O (l) ⇌ H+ (aq) + OH- (aq)

  OR

  H2O (l) + H2O (l) ⇌ H3O+ (aq) + OH- (aq)
• WHAT IS WATER?

  constant, therefore represented by Kw