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

Organic chemistry, illustrate edman degradation and explain its importance

illustrate edman degradation and explain its importance

Reaction, mechanism for the enzyme-catalyzed

mechanism for the enzyme-catalyzed

Atomic structure, the most probable radius for finding the electron in he+

the most probable radius for finding the electron in he+

Nerst equation, Derive Nerst equation for both anode and cathode.

Derive Nerst equation for both anode and cathode.

What are numerous products and application of mica, What are numerous produ...

What are numerous products and application of mica? Applications and products of mica: (i)  Sheet mica: Mainly used in electrical equipment and applications in form of w

List of common functional groups, Consult the inside front cover of the tex...

Consult the inside front cover of the text for a list of common functional groups. (a) nitrile (b) ether

Iupac system of naming organic compounds, IUPAC System of Naming Organic Co...

IUPAC System of Naming Organic Compounds In the IUPAC (International Union of Pure and Applied Chemistry) system, the name of an organic compound contain three parts that are:

Determine the concentration of hydroxide ion in this buffer, In lab, buffer...

In lab, buffers solution based onto a 0.1 M solution of sodium phosphate at pH7.0.  Within this system, there are three of pK A s like:  12.7, 7.21 and 2.12. Determine the conce

What are the de broglies waves, Q. What are the De Broglies waves? Bohr...

Q. What are the De Broglies waves? Bohr anticipated that hydrogen's single electron could orbit at only specific distances from the atom's nucleus. When the electron is in the

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