Students should be able to:
1.7a recall the physical properties of the elements
1.7b recall the simple chemical tests for the elements (paper 3B only)
• restricted to bleaching, displacement reactions and the reaction of iodine with starch
1.7c recall and explain the fact that hydrogen halides are water soluble and acidic in solution
1.7d recall the use of silver ions and aqueous ammonia in the identification of chloride, bromide and iodide ions (paper 3B only)
1.7e understand the reactions of halide salts with concentrated sulphuric acid in relation to the reducing power of the hydrogen halides/halide ions.
• recall of an equation for the reaction of concentrated sulphuric acid with iodides is not required
1.7f recall the existence of the +1 and +5 oxidation states of chlorine in the oxo-anions chlorate(I) and chlorate(V)
1.7g recall the disporportionation of chlorine and of the chlorate(I) ion
1.7h recall the relative strengths of the elements as oxidising agents and understand the application of this to the extraction of bromine from sea water