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

Which of the following set of quantum number is not possible, Which of the ...

Which of the following set of quantum number is not possible:              n             l               m1        m2 (a)         3              2              1

Electrolysis of water in the presence of an indicator., Electrolysis of Wat...

Electrolysis of Water in the Presence of an Indicator • Place ~ 50 mL of the thawed cabbage juice in the same glass container (after rinsing) used in Step 1. • Insert the electro

Amino acids - biomolecules, Amino acids Proteins are a class of biologi...

Amino acids Proteins are a class of biologically significant substance. They are important to virtually all processes in living systems. A few of acids are hormones that offer

Equivalent weight, how do you calculate equivalent weight of salts

how do you calculate equivalent weight of salts

Title: Organic, Show by means of equations and reagents, how the following ...

Show by means of equations and reagents, how the following conversion would be achieved? Propyne to butanoic acid

What is law of definite proportions, Q. What is law of definite proportions...

Q. What is law of definite proportions? A given compound is forever composed of the same elements in the same proportion by mass. This fact is recognized as the law of definit

Periodic table, what are the periodicity of periodic properties in d and f ...

what are the periodicity of periodic properties in d and f block elements?

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