Reactions of the halogens Flashcards
What is the colour of chlorine in water?
Very pale green
What is the colour of bromine in water?
Orange
What is the colour of iodine in water?
Brown
What is the colour of chlorine in hexane?
Very pale green
What is the colour of bromine in hexane?
Orange
What is the colour of iodine in hexane?
Purple
What is the colour of the halides in water?
Colourless
What is the colour of the halides in hexane?
Colourless
What is the order of reactivity?
They decrease in reactivity down the group
What is the reason for the trend in reactivity?
Halogens react by gaining an electrons and atoms further down the group are bigger and the outer shell experiences more shielding so they are less able to attract an electron. Oxidising strength also decreases down the group
How is one element both oxidised and reduced?
It’s oxidation number increases and decreases
What is a disproportionation reaction?
A redox reaction where the same element is oxidised and reduced
What is the equation for the reaction of chlorine with water?
Cl2 + H2O -> HCl + HClO
What does the reaction of chlorine and water produces?
Hydrochloric acid and chloric acid
What is the importance of the reaction of chlorine with water?
It is used in the purification of mains water as chloric acid can oxidise bacterial cell walls and break them down. Also, chlorine gas was used as a chemical weapon in the WW1 trenches as HCl produced corroded mucus membranes
