Combined ScienceCode 5129
Group VII properties
What this topic asks you to be able to do
- Describe chlorine, bromine and iodine, the halogens of Group VII, as diatomic non-metals that show general trends going down the group, limited to: (a) an increase in density (b) a decrease in reactivity
- State how the halogens look at r.t.p.: (a) chlorine – a gas that is pale yellow-green (b) bromine – a liquid that is red-brown (c) iodine – a solid that is grey-black
- Describe the toxic nature of chlorine, Cl2, and of bromine, Br2
- Describe the way chlorine gas, Cl2, can be identified with damp litmus paper
- Outline and account for the reactions in which a halogen displaces other halide ions, and apply these reactions to rank the halogens by reactivity
- State how each halogen looks in aqueous solution: (a) chlorine is colourless (b) bromine is orange (c) iodine is brown
- Describe how halide ions react with acidified aqueous silver nitrate, giving insoluble silver halides, limited to: (a) AgCl, which is white (b) AgBr, which is cream (c) AgI, which is pale yellow
- Predict the properties of the remaining Group VII elements, using information supplied about them