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

Molarity , sulphuric acid can be made with concentration of 99%. However fo...

sulphuric acid can be made with concentration of 99%. However for different industrial process different concentration are used. For a specific industrial requirement, 62% H2SO4 is

Solvent effect of UV, what is the solvent effect on transition metal?

what is the solvent effect on transition metal?

Compounds show high melting and boiling points, Which type of compounds sho...

Which type of compounds show high melting and boiling points: (1) Electrovalent compounds (2) Covalent compounds (3) Coordinate compounds (4) All the three types of co

Synthesis of freon and freon synthesis, explain the synthesis of freon and ...

explain the synthesis of freon and westron i need only the synthesis of those coompound

Iodine value - analysis of oils and fats, Iodine value - Analysis of oils a...

Iodine value - Analysis of oils and fats Iodine value of a oil or fat is a measure of its amount of unsaturation. It is proved as the number of grams of iodine taken up by 100

Expressing quantities in scientific notation, The surface area of the Pacif...

The surface area of the Pacific Ocean is 166000000000000m 2 . Write this quantity in scientific notation. To write the amount in scientific notation move the decimal point to after

F block element, why Zn metal regarded other element

why Zn metal regarded other element

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