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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: jcklwy on March 02, 2020, 11:50:14 PM

Title: Born Haber Cycle and Hess's Law Presentation.
Post by: jcklwy on March 02, 2020, 11:50:14 PM

The following are the instructions for this presentation:

Produce a presentation containing information on a  Born-Haber cycle and an energy cycle for the dissolution of either NaOH or NH4Cl  in water.

In your presentation, you will need to include details such as:

- The meaning of each representative equation required for each of the cycles.
- Use a group 2 chloride or a group 2 oxide in your Born-Haber cycle.
- In the cycles explain how the size and charge of the ions have an impact on the lattice or hydration enthalpies.
- Explain the difference between experimental and actual lattice energies.

I have several questions:
1. how does one come up with a haber cycle for the dissolution of NaOH or NH4CL in water? Isn't the born haber cycle using the formation, atomisation, dissociation, etc enthalpies to find the lattice enthalpy? where does water come into this and if I were to ignore the water what is the natural state of OH i should use for the Haber cycle?

2. It also asks to use a group 2 chloride oxide in your born-haber cycle. When and where is this supposed to be used?

I would really appreciate it if anyone could give even a little guidance on how to approach this prsentation.
Thank you.

Title: Re: Born Haber Cycle and Hess's Law Presentation.
Post by: Borek on March 03, 2020, 03:01:06 AM

I think you are misreading the instruction. It doesn't say "Born-Haber cycle for dissolution", it says "Born-Haber cycle and an energy cycle" - there are two separate things that you should talk about.