How would you answer this chemistry AS level question?

Suggest why the bond energy values decrease in the order HCl > HBr > HI?

From savemyexams.co.uk

How I would do it is:

As we go from HI to HCl, there is an increase as the strength of the covalent bonds increase, which could be due to their being a greater electron density between teh nuclei of the two atoms, hence greater attractive forces between the nuclei and electrons, thus resulting in the atoms being pulled closer together and there being a stronger covalent bond.

(edited 2 years ago)

Reply 1

youareloved

6

Going down group 7, the C-halogen bond breaks easier. Therefore, less energy is required to overcome this force.

Reply 2

Pigster

20

Original post by sweetescobar

Suggest why the bond energy values decrease in the order HCl > HBr > HI?

From savemyexams.co.uk

How I would do it is:

As we go from HI to HCl, there is an increase as the strength of the covalent bonds increase, which could be due to their being a greater electron density between teh nuclei of the two atoms, hence greater attractive forces between the nuclei and electrons, thus resulting in the atoms being pulled closer together and there being a stronger covalent bond.

Which spec do you do? Not all spec will ask that.

It is all to do with the attraction between the halogen nucleus the shared pair. Which is most influenced by the number of shells.

Reply 3

sweetescobar

OP

15

Original post by Pigster

Which spec do you do? Not all spec will ask that.

It is all to do with the attraction between the halogen nucleus the shared pair. Which is most influenced by the number of shells.