Illustrate born-haber cycle, Chemistry

Assignment Help:

Q. Illustrate Born-Haber cycle?

Boron is always covalent and does not   form,B3+ ions, because' the energy required to remove three electrons is very high.  Many simple compounds of A1 and Ga like AlCl3 and GaCl3 are also covalent when anhydrous. However, in solution, the large amount of hydration energy evolved compensates the high ionisation energy and all the' metal ions exist in a hydrated state.

This can be explained with the help of Born-Haber cycle as given below. However, this is a simplified approach given only on the bas; of enthalpy changes, whereas the direction and extent of any reaction depend on the free energy changes which take into account changes both in enthalpy and entropy.

365_Illustrate Born-Haber cycle.png

Thus, despite the large ionisation energies of aluminium, the enthalpy of' solution of  AlCl3 has a large negative value. Therefore, in aqueous solution, AIC3 exists as AI3+(aq) and Cl-(aq). It might be thought that the same argument would apply to BCI3; But to make the enthalpy of solution of BCl3 nethalpy the enthalpy of hydration of B3+ should be - 6009 KJ which is unlikely for the small B3+cation. Therefore, BC13 hydrolyses in aqueous solution to give boric acid and not B3+ (aq).

BCl3 + 3H20 -----------------------------------> H3B03 + 3HCI


Related Discussions:- Illustrate born-haber cycle

Phenol, gattermann koch reaction mechanism

gattermann koch reaction mechanism

S-block element, lithium and beryllium markedly different from other member...

lithium and beryllium markedly different from other members of their respectively groups

General , Match the compounds below with the type of bonding each predomina...

Match the compounds below with the type of bonding each predominately exhibit. Question 3 options: NaCO3 NaBr SOCl2 CH4 1. ionic bonding 2. covalent bonding

What numerical prefixes indicate in ligands, Q. What Numerical prefixes ind...

Q. What Numerical prefixes indicate in ligands? In any complex species, the ligands are quoted in alphabetical order, without regard to charge, before the name of the central m

Aldol condensation - aldehydes and ketones, Aldol condensation - Aldehydes ...

Aldol condensation - Aldehydes and Ketones (a) This reaction occurs between two molecules of carbonyl compounds; one molecule should have at least two α-hydrogen sets. In that

The maximum energy is present in any electron, The maximum energy is presen...

The maximum energy is present in any electron at: (1) Nucleus      (2) Ground state (3) First excited state (4) Infinite distance from the nucleus Ans: Infinite dis

Hubles Test, Explain in brief hubles test for any test splution

Explain in brief hubles test for any test splution

Gas laws , what is the volume of a gas when the temperature is raised to 25...

what is the volume of a gas when the temperature is raised to 25 degrees celcius fro STP?

Explain about the impact extrusion, Explain about the Impact extrusion ...

Explain about the Impact extrusion Blank is placed over the die and pressed by punch. Metal is squirted upward round the punch. Thickness of the part is fixed by the gap bet

Electrochemical cells, I have this chemistry assignment. It basically says,...

I have this chemistry assignment. It basically says, "study and make a report on any two types of electrochemical cells". What do I do? I have no idea so please, I need some help.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd