Coordination number and geometry, Chemistry

Assignment Help:

Coordination number and geometry

 

Binary compounds are ones with two different elements present. 'Simple' crystal structures can be classed as ones in which each atom (or ion) is surrounded in a regular way by atoms (or ions) of the other kind. Even with this limited existence many structures are possible.

Although many are achieved with ionic compounds, some of these structures are shown by compounds with covalent bonding, and a discussion of the bonding factors involved in favoring one structure rather than another is deferred to

When the two elements B and A are not equivalent A is drawn smaller and with shading. In ionic compounds this is more general the metallic (cationic) element. If the role of cations and anions is reversed we speak of the anti-structure: thus Li2O has the, Cs2O the anti-CdI2 structure and anti-fluorite (CaF2) structure.

From the local point of view of each atom the most important characteristics of a structure are the coordination geometry and coordination number (CN). In the examples described these are the same for all atoms of the same type. Coordination numbers can be compatible with the stoichiometry. In AB both B and A have the same CN, the examples shown being

 

Zinc blende (4:4); Rocksalt (6:6); NiAs (6:6); CsCl (8:8).

 

When the stoichiometry is AB2 the CN of A has to be twice that of B:

 

Rutile (6:3); CdI2 (6:3); Fluorite (8:4).

 

 


Related Discussions:- Coordination number and geometry

The phosphate of a metal has the formula mpo4, The phosphate of a metal has...

The phosphate of a metal has the formula MPO4 .The formula of its nitrate will be: (1) MNO 3                                                   (2)  M 2 (NO 3 ) 2

Find the number of intensive variables, Find the number of intensive variab...

Find the number of intensive variables? Consider the lime-kiln process CaCO 3 (s) → CaO (s) + CO 2 (g) Find the number of intensive variables that can be varied independen

Extraction of metals, metals iron, aluminium, copper, gold, etc. have great...

metals iron, aluminium, copper, gold, etc. have great industrial significants. which are their important ores? important alloys of iron, aluminium and copper and their uses.

Answers, which among the following species have the same no of electrons in...

which among the following species have the same no of electrons in its outermost as well as penultimate shell

Radioanalytical methods, Radioanalytical methods: Radioanalytical meth...

Radioanalytical methods: Radioanalytical methods using radiotracers and activation analysis are more sensitive and specific because of ease of detection of nuclear radiation.

Uses of nitro alkanes or nitroparaffins, Uses of Nitro alkanes or Nitropara...

Uses of Nitro alkanes or Nitroparaffins (1) Nitro alkanes are used as solvents for polar substances such as cellulose acetate, synthetic rubber etc. (2) Nitro alkanes are us

Who proposed law of mass action, Laws of mass action were proposed by Gulbe...

Laws of mass action were proposed by Gulberg and Waage. The rate of chemical reaction is directly proportional to the product of the active masses of the reactants (molar concentra

Origin of charge on colloidal sol, Colloids are either positively charged o...

Colloids are either positively charged or negatively charged. But What are the various factors responsible for charge on the colloidal sols?

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