Reactions of Halide Ions Flashcards
A disproportionation reaction is a reaction in which
the same species is both oxidised and reduced
The reaction of chlorine with dilute alkali is an example of a
what happens in this reaction
example of a disproportionation reaction
In these reactions, the chlorine gets oxidised and reduced at the same time
Different reactions take place at different temperatures of the dilute alkali
Chlorine in cold alkali (15 oC)
The reaction that takes place is:
Cl2(aq) + 2 NaOH (aq) > NaCl(aq) + NaClO + H20 (l)
Chlorine in cold alkali (15 oC)
The reaction that takes place is:
ionic equation
Cl2 =0
one chlorine in NaCl reduced -1
other chlorine in NaClO is oxidised +1
other ions NaOH-
Chlorine can be used to clean water and make it drinkable
The reaction of chlorine in water is a disproportionation reaction in which the chlorine gets both oxidised and reduced
This reaction is important in the purification of water for drinking and swimming pools
EQUATION
Cl2(g) + H20(l) > HCl(l) + HCLO
The disproportionation reaction of chlorine with water in which chlorine gets reduced to HCl and oxidised to HClO
Chloric(I) acid (HClO des what to water
sterilises water by killing bacteria
Chloric acid can further dissociate in water to form ………….
and equation
ClO- (aq):
HClO (aq) → H+ (aq) + ClO- (aq)
ClO- (aq) also acts as a………… in the water
sterilising agent cleaning the water
Chlorine is used in water treatment to kill bacteria
It has been used to treat drinking water and the water in swimming pools
The benefits to health of water treatment by chlorine by its killing of bacteria outweigh its risks of
outweigh its risks of toxic effects and possible risks from the formation of chlorinated hydrocarbons
In shallow swimming pools chlorine is rapidly lost from the water, so the chlorine has to be topped up on a regular basis adding to cost
This is because it is more exposed to
sunlight
In sunlight, the following reaction occurs:
In sunlight, the following reaction occurs:
2Cl2 (g) + 2H2O (l) → 4HCl (aq) + O2 (g)
Adding chlorine to a water supply is an effective way to make the water safe to drink as it forms the sterilising agent HClO which in turn dissociates in water into another sterilising agent, ClO-(aq)
