11852 [Turn over 10 Which species is the most powerful oxidising agent? A Bromide B Bromine C Chloride D Chlorine 11852 Section B Answer all six questions in the spaces provided. 11 Water can act as an acid or as a base. It can either lose or gain hydrogen ions. (a) State and explain the shape of a water molecule. [3] (b) Water can react with hydrogen ions forming hydroxonium ions, H3O+. (i) Draw a dot and cross diagram to show the bonding in a hydroxonium ion, showing all the outer shell electrons. [2] 11852 [Turn over (ii) Suggest why the bond angle in the hydroxonium ion is greater than the bond angle in water. [2] (iii) Suggest why the hydroxonium ion does not react with a hydrogen ion to form H4O2+. [1]