Dative bonding

[Questionasker]

Hey, I was looking at the reaction between ammonia (NH₃) and hydrochloric acid (HCl). Apparently from the diagram I saw the hydrogen from HCl would get drawn towards the nitrogen, leaving an electron behind for the chlorine. Why does this happen? Do lone pair electrons have a larger electrostatic force?

P.S forgive me if I've i may of done something wrong, I'm new to this website.

[studiot]

1 hour ago, Questionasker said:

Hey, I was looking at the reaction between ammonia (NH₃) and hydrochloric acid (HCl). Apparently from the diagram I saw the hydrogen from HCl would get drawn towards the nitrogen, leaving an electron behind for the chlorine. Why does this happen? Do lone pair electrons have a larger electrostatic force?

P.S forgive me if I've i may of done something wrong, I'm new to this website.

No problem, this is a good  question and you have found the correct subsection.

Well done and welcome . +1

 

Both electrons forming a covalent bond need not come one from each atom.
One atom may supply them both.

This type of bond is called a dative covalent bond.

Now what  you are referring to was probably in solution.
In solution the HCl is fully dissociated (it is a strong acid) to produce H⁺ and C^l- ions.
The lone pair (do you understand lone pairs ?) of the nitrogen in the neutral ammonia  and the H⁺ ion are  drawn towards each other to form a dative covalent bond.

 

Does this help?

Edited March 16, 2020 by studiot

[Questionasker]

Hi studiot, thank you for the +1.

I have a 'decent' understanding of what lone pair electrons are. They have the strongest rupulsion and therefore causes the structures of some molecules to be different E.G Tetrahedral shape. It's just I don't understand why the H⁺ decides to go to the lone pair electrons from the nitrogen. Why did it move? It had a full outer shell from both the chlorine electron and its own electron. To be more specific:

Why did the H⁺ move towards the nitrogen atom when it had a full outer shell with chlorine?

 

 

[studiot]

On 3/16/2020 at 6:51 PM, Questionasker said:

I have a 'decent' understanding of what lone pair electrons are. They have the strongest rupulsion and therefore causes the structures of some molecules to be different E.G Tetrahedral shape.

This is sort of true.

The repulsion is against other orbitals in the same atom or molecule.
It is not against other species, particularly not positive ions.
And clearly it is against orbitals that have electrons in them not empty ones.

More on this would be a story for another thread.

 

On 3/16/2020 at 6:51 PM, Questionasker said:

It's just I don't understand why the H⁺ decides to go to the lone pair electrons from the nitrogen. Why did it move? It had a full outer shell from both the chlorine electron and its own electron. To be more specific:

Why did the H⁺ move towards the nitrogen atom when it had a full outer shell with chlorine?

 

You need to distinguish between neutral atoms and molecules and ions.

HCl is a neutral covalently bonded molecule.
When it ionises in solution that is when the H⁺ appears and is electrostatically attracted by the lone pair of the Nitrogen which is , as you say, exposed by the tetrahedral shape of the ammonia.
The H+, of course, doesn't have any electrons in its shells.

Edited March 19, 2020 by studiot

[Questionasker]

Thank you for your reply.

So, just to clarify, the lone pair of electrons would produce a 'larger' electrostatic force than a singular electron from the chlorine. This would therefore cause the hydrogen ion to interact to the lone pair of electrons. Is this right?

 

Also, how come a lone pair of electrons have a stronger repulsion than a pair of electrons that are provided by another atom and an atom that its going to covalently bond to?

[studiot]

8 minutes ago, Questionasker said:

So, just to clarify, the lone pair of electrons would produce a 'larger' electrostatic force than a singular electron from the chlorine. This would therefore cause the hydrogen ion to interact to the lone pair of electrons. Is this right?

No, it does not work like that.

It is better to think in energy terms than in 'force' terms.

Bonding action is not really explained without quantum theory, which is an energy theory.

(It's actually easier that way as well).

But remember I said 'within the same molecule or ion'

The lone pair and the chlorine electron are never in the same molecule.

 

8 minutes ago, Questionasker said:

Also, how come a lone pair of electrons have a stronger repulsion than a pair of electrons that are provided by another atom and an atom that its going to covalently bond to?

Another thread please  e.g. How a lone pair works ?"

Edited March 19, 2020 by studiot

[studiot]

Did you want to pursue this?

I see it links in with your discussion with Hypervalent Iodine.

[Questionasker]

Hi, sorry for the incredibly long reply.

Not quite. I was just, in general, curious about why hydrogen would abandon its shared electron with chlorine to share 2 lone pair electrons with ammonia.

[studiot]

15 minutes ago, Questionasker said:

Hi, sorry for the incredibly long reply.

Not quite. I was just, in general, curious about why hydrogen would abandon its shared electron with chlorine to share 2 lone pair electrons with ammonia.

 

I hope you gathered from the discussion that 'hydrogen' doesn't do this.

 

I also hoped you would gather the need for greater specivity in Science and scientific discussion.

(Your latest thread suggests otherwise as responders are struggling because you haven't defined your terms tightly enough.)
 

Edited March 30, 2020 by studiot

[Questionasker]

Ok, I'd like to sincerely apologize for wasting your time. I had the wrong idea of what would happen to the reaction between Ammonia and hydrochloric acid. I had a completely idiotic idea of what would happen. Thank you for trying to reason with my stupidity.

As for your criticisms, i'll be sure to be much more specific with my questions next time.

Once again, thank you.

[studiot]

1 hour ago, Questionasker said:

Ok, I'd like to sincerely apologize for wasting your time. I had the wrong idea of what would happen to the reaction between Ammonia and hydrochloric acid. I had a completely idiotic idea of what would happen. Thank you for trying to reason with my stupidity.

As for your criticisms, i'll be sure to be much more specific with my questions next time.

Once again, thank you.

It's not stupidity if you don't know something but if you ask that's wisdom. +1

The more you put in the more you will get out.

Or

The better you frame your question the better the answer you will receive.

 

[Questionasker]

I understand, thank you for your advise.

😄