Urgent - Halogens: physical properties and redox reactions Watch

SilvaStag
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Hi, I’m am really stuck on these questions - thank you for any help - I have done parts a b and d on question 2. But none on question three...


(3) When sodium hydroxide reacts with a halogen, a disproportionation reaction takes place

(a) What is a disproportionation reaction?
(b) Write a balanced equation, with state symbols, for the disproportionation of bromine water when reacting with aqueous sodium hydroxide portionation reaction. bromine water
(c) Use oxidation numbers and your answer to (b) to demonstrate that this is a disproportionate reaction.
(d) Describe what you would observe if you added drops of sodium hydroxide solution to

(4) When halogens react with metals, a redox reaction occurs. For example, iron and chlorine react together according to this equation: 2Fe (s)+3Cl2 ) 2FeCl3()

(a) Give the name of the product.
(b) Explain how this equation shows chlorine to have acted as an oxidising agent.
(c) Describe the trend, going down group 7, in the strength of the elements as oxidising agents.
(d) Explain this trend in terms of the relative ease, going down the group, of forming a 2 9 halide ion from a halogen atom.
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BobbJo
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3a) When a substance is simultaneously oxidised and reduced

b) Br2(aq) + 2NaOH(aq) -> NaBr(aq) + NaBrO(aq) + H2O(aq)

c) Br in Br2 has O.N 0
Br in NaBr has O.N -1
Br in NaBrO has O.N +1.
Hence bromine has been oxidised and reduced.

d) To what?

4a) iron (iii) chloride

b) Oxidation number of iron increases from 0 to +3.

c) Down group 7, halogens become weaker oxidising agents.

d) 2 9 halide ion? What?
Down the group, number of electron shells increases. Shielding effect increases. Effective nuclear charge decreases. Atomic size increases. Hence nucleus has weaker force of attraction on electron and it is more difficult for the halogen to accept an electron.
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SilvaStag
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(Original post by BobbJo)
3a) When a substance is simultaneously oxidised and reduced

b) Br2(aq) + 2NaOH(aq) -> NaBr(aq) + NaBrO(aq) + H2O(aq)

c) Br in Br2 has O.N 0
Br in NaBr has O.N -1
Br in NaBrO has O.N +1.
Hence bromine has been oxidised and reduced.

d) To what?

4a) iron (iii) chloride

b) Oxidation number of iron increases from 0 to +3.

c) Down group 7, halogens become weaker oxidising agents.

d) 2 9 halide ion? What?
Down the group, number of electron shells increases. Shielding effect increases. Effective nuclear charge decreases. Atomic size increases. Hence nucleus has weaker force of attraction on electron and it is more difficult for the halogen to accept an electron.
3a) to Bromine Water

4d) forming a halide ion froma halogen atom.

Thank You!!
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BobbJo
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(Original post by SilvaStag)
3a) to Bromine Water

4d) forming a halide ion froma halogen atom.

Thank You!!
3a) bromine water turns from red-brown to colourless

4d) already answered
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