The Student Room Group
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>

What is going on in this reaction?

In the following reaction between Sodium and Chlorine, the product is Sodium Chloride.

Capture.PNG

My question is, what happens to the Cl2 bit? Surely the product must also have 2 in it? Or is it something to do with the charges? (if that's even relevant)??
Reply 1
Avatar for Kerch
Kerch
8
The requirement for it to be a valid reaction is just that the number of atoms of each element is conserved, which it is here (both sides have 2 Na and 2 Cl).

For this reaction, the bond between the two Cl atoms in the Cl2 molecule has to be broken. There's nothing stopping you writing down a reaction like that. In practice, breaking this bond has a certain energy barrier, but this can be overcome depending on the conditions (e.g temperature) and whether or not the final state has a lower energy.
For the Cl: Cl2 --> 2Cl+

The covalent bond is broken and forms two positive chloride ions, which form an ionic bond with sodium.
Original post by SheldonWannabe
For the Cl: Cl2 --> 2Cl+

The covalent bond is broken and forms two positive chloride ions, which form an ionic bond with sodium.


choride ions are negative.

The sodium atoms donate electrons to the chlorine atoms making sodium ions (positive) and chloride ions (negative)
Original post by charco
choride ions are negative.

The sodium atoms donate electrons to the chlorine atoms making sodium ions (positive) and chloride ions (negative)


Haha! yes, course. Sorry, been awake for too long.
Reply 5
Avatar for tohaaaa
tohaaaa
OP
16
Original post by SheldonWannabe
For the Cl: Cl2 --> 2Cl+

The covalent bond is broken and forms two positive chloride ions, which form an ionic bond with sodium.


So could you write NaCl as 2Na-Cl+?
Also, why do the bonds between Cl2 break? :/
Reply 6
Avatar for Kerch
Kerch
8
Original post by tohaaaa
So could you write NaCl as 2Na-Cl+?
Also, why do the bonds between Cl2 break? :/


It seems strange if you imagine the molecule as two balls (atoms) with sticks (bonds) between them, because then the bond has to suddenly break, but in reality there is no exact moment in which the bond breaks.

There is really a 'cloud' of electrons surrounding the nuclei of the atoms which creates the bond, so it can be broken gradually. As the atoms in the Cl2 molecule move around (perhaps due to thermal vibrations), they may visit a location where they prefer to bond with the Na atoms near them instead, and they can then separate from each other.

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you