Question

Second ionization enthalpy of fluorine should be less than nitrogen. Isn't it ?

Answer 1

@mayankdevnani

Answer 2

No fluorine's enthalpy should be higher. Do you have any reason to support your statement?

Answer 3

Okk , I have a sound reason too for my statement ...

Answer 4

Look...
The configuration for fluorine is
2s2 2p5.
Ryt??
Now if we take out an electron we will have it 2s2 2p4 ..
Another electron would cost its electronic configuration to be modified in the sense thay it becomes 2s2 2p3
Now..the p orbital here is half filled ...
Which is definitely a good condition for it to lose an electron after first ionisation..
So i think it should have presumably lower ionization enthalpy than nitrigen

Answer 5

@vijeya3

Answer 6

No,I seriously came up with reasoning but the ans says it is the reverse ..I mean it's given that nitrogen has more second ionization enthalpy than that of fluorine

Answer 7

@chmvijay @aaronq

Answer 8

@ParthKohli

Answer 9

Whenever you are to compare second ionisation enthalpies, compare IE1s of the previous elements.

So compare those of oxygen and carbon.

Answer 10

@parthkohli is my reasoning wrong??

Answer 11

Well ! If we go by ur way too then also we will be having same result

Answer 12

IE1 (oxygen) > IE1 (carbon)
so
IE2 (fluorine) > IE2 (nitrogen)

Answer 13

Becoz we know that oxygen has
2s2 2p4 configuration.. Now remove an electron 2p3
Which is actually more stable so less energy would be required to remove the elctron from oxygen as compared to carbon

Answer 14

Look up a table or something. Ionisation energy of oxygen is greater than that of carbon.

Answer 15

The priority you're giving to half-filled subshells is way more than it actually is.

Answer 16

I know that you are talking in sense of moving across a period means a increase in ionization enthalpy...Isn't it?

Answer 17

An*

Answer 18

Yes, that trend is more important.

Answer 19

Seriously?
We were taught that rely on the concept based..and not the table

Answer 20

It's always that we try to find the concepts based on the observations. We can't change the observations based on our logic.

Answer 21

So as per you the first ionization enthalpy of nitrogen has to be less than that of oxygen...
By the table formula we can say that ...ryt?

Answer 22

Oxygen has greater first ionization energy than Nitrogen. But we have to compare oxygen with carbon first ionization energy. Because Nitrogen forms carbon and flourine forms oxygen and oxygen has greater ionization energy than carbon.

Answer 23

Well the main reason why flourine's ionization energy is greater than nitrogen depends on three reasons.
1.Size of the atom
As you go across the period, the atomic radius decreases making flourine much smaller than nitrogen. Same applies for their respective +2 ions. Since they are losing electrons there is a lesser repulsion in the valence shells giving an equal decrease to their sizes. Since the size of flourine atom is much smaller, it requires more energy to counter the attraction from the nucleus.
2. Size of the nuclear charge
Size of the nuclear charge is greater in flourine.
3.Shielding effect
Since both of them are occupying the same orbitals and the same shells, as a result shielding effect remains constant.

And about your argument, you gave earlier, when we are measuring the floruine's second ionization energy, we are actually measuring the energy required to knock out the electron from 2s2 2p4 configuration. So the half filled p-orbital arguement here is invalid.