disproportionate reactions

Question 1

disproportion reaction

Answer 1

element Is both oxidised and receded in the same reaction

Question 2

what elements will displace each other in a displacement reaction

Answer 2

A halogen will displace (oxidise) the halide from a solution if it is below it on the periodic table

Question 3

How to test for halides

Answer 3

1- add dilute nitric acid,
2- Add silver nitrate ( ag No3) - it reacts with the halide ion present
3- precipitate is formed of silver halide

Question 4

The colour of ppt and the solubility in diff ammonia solutions when testing for halides.

Answer 4

cl- forms white ppt and dissolves in dilute nitric acid
br- forms cream ppt and dissolves in conc nitric acid
I- forms cream ppt and is insoluble in conc nitric acid.

Question 5

How to confirm the halide present

Answer 5

add ammonia solution - diff solubility for diff halides

Question 6

Halogen disproportionate reactions with…

Answer 6

• cold dilute alkali solutions -oxidised and reduced.

Question 7

what happens when u mix chlorine with sodium hydroxide

Answer 7

mix chlorine gas with cold dilute sodium hydroxide you make sodium chlorate solution (bleach)
- 2NAOH + CL2 -> NACLO + NACL + H20

Question 8

benefits of sodium chlorate solution (bleach)

Answer 8

water treatments (kill bacteria) , bleach paper and textiles, cleaning

Question 9

what happens when you mix chlorine and water

Answer 9

• when you mix chlorine and water it undergoes disproportionation reaction. (0 to -1, +1)
• mixture of HCL and HCLO (Chloric acid) produced
• chloric acid ionises to form chlorate ions
• chlorate ions kill bacteria

Question 10

Benefits of adding chlorine to water

Answer 10

-kills disease causing microorganisms
- prevents reinfection
- prevents algae growth - bad smells, taste, removes discolouration

Question 11

Risks of adding chlorine to water

Answer 11

-hazard of toxic chlorine gases - respiratory issues
- chemical bruns - cl(l)
- possible risk of cancer from formation of chlorinated hydrocarbons (eg; decomposition of plants in water)

Question 12

alternatives to using chlorine as a method of killing microorganisms

Answer 12

• ozone (03) (good oxidising element - good at killing microorganisms)
• Uv -> damages DNA of micro-organisms, ineffective in cloudy water though.

Question 13

what ppt formed (displacement reaction) of ammonium carbonate and barium nitrate

Answer 13

a white ppt of barium carbonate