The halogens and atom economy

Why is dilute nitric acid added before testing for halide ions

to remove other ions which may interfere with the reaction.

What are the colours of the silver halide precipitates

AgF - soluble

AgCl - white

AgBr - cream

AgI - yellow

How can the identification of halides in solution be better supported

AgCl dissolves in dilute ammonia solution, AgBr dissolves in concentrated ammonia solution, AgI does note dissolve in ammonia solution

What are the risks associated with transporting and storing chlorine

• Toxic and corrosive

• Irritates respiratory system

• Oxidising agent so increases fire risks

How can the dangers of chlorine be minimised

• Transport with care

• Keep away from the eyes and skin

• Do not inhale chlorine

• Keep away from flammable objects

How is chlorine stored and transported

As a liquid under pressure in small cylinders

What are the uses of chlorine

• Sterilises water and kills disease causing microorganisms making water sage to drink and swim in

• Used to make bleach

Atom economy

A measure of the proportion of reactant atoms that become part of the desired product in the balanced chemical equation

% atom economy equation

(molecular mass of desired product / sum of molecular mass of all products) x 100

Benefits of reactions with high atom economies

Produce less waste making them cheaper and more environmentally friendly.