Which among the following factors is most important in making fluorine,the strongest oxidising halogen:

(A)bond dissociation energy

(B)ionisation energy

(C)hydration enthalphy

(D)electron affinity

i need explanation

D. e aff. Bcoz F has genarlly -1 oxidation state amoung halogen family so it oxidies easily

strong oxidising agent means which reduces itself and oxidises others..i m solving this que by elimination

(D)electron affinity- in modern periodic table  halogens have max. electron affinity in corresponding period but b/w halogens Cl has max. electron affinity as we move from 2p to 3p electron affinity inc. in p block due repulsion b/w incominig electron and already present electrons ,since their size is less

so D cannot be the ans.

(A)al the halogens exist in molecular form so for reduction of halogens it must be converted into atom,so less the bond dissociation energy more easier oxidation of halogens...in fluorine 2p-2p overlapping is there so it is strong overlapping compared to other halogens so F₂ bond doesn't break easily,hence F must not be strongest oxidisng agent but it is as given in que

so (A) cannot be the ans.

(B)reduction of self means electron affinity so no relation with ionisation energy

so (B) cannot be the ans.

(C) so C must be the ans.

but i m not understanding the relation b/w hydration enthalphy and reduction of self...

plz help...

Hi Suchita,

What you have mentioned is perfectly right.

Electron affinity of F is less than that of Cl.

The right answer is Hydration Energy (ie the energy released when gaseous ions convert to aqueous ions, when dissolved in water).

For a detailed explanation, you should visit this website:

http://www.chemguide.co.uk/inorganic/group7/halogensasoas.html

The reasons in Chemistry are always given to support the experimental results. So in Chemistry you need to give a logical reason for the experimental result obtained (you would have to do that much more in Engineering).

So you should look at that site, as to why Fluorine is a stronger oxidising agent than cluorine, even though what you've tried to explain is logical, there are factors that come into picture (the Hydration Enthalpy, is the greatest for F, making it a strong Oxidising agent)

For inorganic Chemistry and Organic Chemistry, you need to commit these things to memory.

Hope that helps.

All the best.

Regards,

Ashwin (IIT Madras).

Approved