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IAL Chemistry unit 1 may 23rd

Ysph06

Ysph06

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lateefa3 said:
what did you guys write for the question where they asked why f-f bond energy is greeater than cl-cl bond?the two mark question?
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F-F bond length is shorter, since F has a smaller radii than Cl. So more nuclear attraction between the shared pair of electrons and nucleus.
And for the second part, it states that why F-F bond is lower than Cl-Cl, with a table with values given. I think that's because since F-F bond is very short, the lone pairs are brought close together, to experience repulsion, thus weakening the bond, hence bond enthalpy of F-F is less
 
lateefa3

lateefa3

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Ysph06 said:
F-F bond length is shorter, since F has a smaller radii than Cl. So more nuclear attraction between the shared pair of electrons and nucleus.
And for the second part, it states that why F-F bond is lower than Cl-Cl, with a table with values given. I think that's because since F-F bond is very short, the lone pairs are brought close together, to experience repulsion, thus weakening the bond, hence bond enthalpy of F-F is less
Click to expand...

i wrote bout the f-f radius smaller, but thats not all i wrotee i wrote that there is no screening of outer electrons by inner shelss as there is in the chlorine atoms and that fluorine has a higher nuclear charge as a result its harder to break the f-f bond and the energy needed is more that cl-cl bond.. does it make sense?
although i know ishouldve mentioned bout screening tho.
 
Ysph06

Ysph06

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lateefa3 said:
i wrote bout the f-f radius smaller, but thats not all i wrotee i wrote that there is no screening of outer electrons by inner shelss as there is in the chlorine atoms and that fluorine has a higher nuclear charge as a result its harder to break the f-f bond and the energy needed is more that cl-cl bond.. does it make sense?
although i know ishouldve mentioned bout screening tho.
Click to expand...
*Cl has a greater nuclear charge than F since Cl has more protons...
Down group 7, shielding/screening effect increases as electrons are added to new shells. The increase in nuclear charge is outweighed by the increase in screening down the group, so yeah outer electron is held less strongly by the nucleus. So less nuclear attraction. This mostly relates to the ionization energy trend, which is why i didn't write much detail about it. Since question asked for the reason for the difference in bond energies, so that mainly had to deal with the atomic radii and the reasons for it, I guess.
 
lateefa3

lateefa3

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Ysph06 said:
*Cl has a greater nuclear charge than F since Cl has more protons...
Down group 7, shielding/screening effect increases as electrons are added to new shells. The increase in nuclear charge is outweighed by the increase in screening down the group, so yeah outer electron is held less strongly by the nucleus. So less nuclear attraction. This mostly relates to the ionization energy trend, which is why i didn't write much detail about it. Since question asked for the reason for the difference in bond energies, so that mainly had to deal with the atomic radii and the reasons for it, I guess.
Click to expand...
i wrote bout the atomic radii too, so wha do you think will i get marks cut?:/
 
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