13147 16 Strontium and magnesium are both s-block elements. The chemistry of the two elements is very similar but strontium is significantly more reactive. Strontium oxide and magnesium oxide are both basic and will neutralise dilute nitric acid to form nitrates. (a) (i) Deduce the electronic configuration of a strontium atom and a strontium cation: atom cation [2] (ii) Suggest why strontium is more reactive than magnesium. [2] (b) Write an equation for the reaction of strontium with water. [1] (c) Write an equation for the reaction of strontium oxide with dilute nitric acid. [2] 13147 [Turn over (d) It is possible to distinguish between solutions of magnesium nitrate and strontium nitrate by adding a solution which contains hydroxide ions. (i) What would be observed when a few drops of sodium hydroxide solution were added separately to a solution of magnesium nitrate and a solution of strontium nitrate? [2] (ii) Write an ionic equation, with state symbols, for a reaction which occurs in (d)(i). [2] (iii) Suggest an alternative solution which could be used, instead of a solution which contains hydroxide ions, to distinguish between solutions of magnesium nitrate and strontium nitrate. [1]