inorganic chemistry - what's the order of oxidising strength of the oxyacids of chlorine_ -...

sign up log in tour help Take the 2minute tour × Chemistry Stack Exchange is a question and answer site for scientists, academics, teachers and students. It's 100% free, no registration required. What's the order of oxidising strength of the oxyacids of Chlorine? What I have been told is that the of the four oxyacids of Chlorine increase in the order . acidity I have also been told that the oxidising strength goes in the reverse order. In my knowledge acidic strength should increase with oxidising strength. Where am I going wrong? For your reference, the Ka values of the acids are as follows: 1. 2. 3. 4. inorganicchemistry periodictrends edited Aug 29 at 12:57 Ben Norris 13.2k 19 60 asked Aug 29 at 9:23 user7624 16 1 1 – Don't you mean the oxyacids , , , and ? Philipp Aug 29 at 12:31 1 Answer For many acids, the proton is the oxidizing agent. For example, in the oxidation of zinc with , the oxidizing agent is . However, for some acids, the conjugate base (anion) is also an oxidant (and usually a more powerful oxidant than . The oxyacids of chlorine are all oxidizing agents through their anions, as is nitric acid and some others: In the above example, hypochlorite is the oxidizing agent. For the oxyacids of chlorine and others, the strength of the oxidizing agent is independent of the strength of the acid. answered Aug 29 at 13:06 Ben Norris 13.2k 19 60 – Why exactly would the proton often times be a weak oxidizer and why exactly would the conjugate bases sometimes be good oxidizers? Isn't the formation of H2 entropically favorable? Dissenter Aug 29 at 16:07 – Formation of is entropically favorable, but so is conversion of to (three particles from 2). Additionally, you cannot ignore the contribution to spontaneity from . enthalpy Ben Norris Aug 30 at 13:25

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strength of oxyacids

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What'stheorderofoxidisingstrengthoftheoxyacidsofChlorine?

WhatIhavebeentoldisthatthe ofthefouroxyacidsofChlorineincreaseintheorder .acidity )0$M )0$M

)0$M

)0$M

Ihavealsobeentoldthattheoxidisingstrengthgoesinthereverseorder.Inmyknowledgeacidicstrengthshouldincreasewithoxidisingstrength.WhereamIgoingwrong?

Foryourreference,theKavaluesoftheacidsareasfollows:

1. )0$M g

2. g)0$M

3. g)0$M

4. g)0$M

inorganicchemistry periodictrends

editedAug29at12:57BenNorris13.2k 19 60

askedAug29at9:23user762416 1

1 Don'tyoumeantheoxyacids ,)$M0 ,)$M0

,and)$M0

?)$M0

Philipp Aug29at12:31

1Answer

Formanyacids,theproton istheoxidizingagent.Forexample,intheoxidationofzincwith,theoxidizingagentis .)

)$M )

;O )

;O

)

However,forsomeacids,theconjugatebase(anion)isalsoanoxidant(andusuallyamorepowerfuloxidantthan .Theoxyacidsofchlorinearealloxidizingagentsthroughtheiranions,asisnitricacidandsomeothers:)

;O 0 )

0$M

;O

)

$M

Intheaboveexample,hypochloriteistheoxidizingagent.Fortheoxyacidsofchlorineandothers,thestrengthoftheoxidizingagentisindependentofthestrengthoftheacid.

answeredAug29at13:06BenNorris13.2k 19 60

Whyexactlywouldtheprotonoftentimesbeaweakoxidizerandwhyexactlywouldtheconjugatebasessometimesbegoodoxidizers?Isn'ttheformationofH2entropicallyfavorable? Dissenter Aug29at16:07

Formationof isentropicallyfavorable,butsoisconversionof)

to )0$M (threeparticlesfrom2).Additionally,youcannotignorethecontributiontospontaneityfrom .0)

$M

enthalpy BenNorris Aug30at13:25