Divisibility rule: Difference between revisions

From formulasearchengine
Jump to navigation Jump to search
← Older edit
en>Black Yoshi
Undid revision 593701569 by Kim0625L (talk) Unnecessary.
en>MrOllie
Reverted to revision 641444579 by Ilmari Karonen (talk). (TW)
 
(One intermediate revision by one other user not shown)
Line 1: Line 1:
The '''Born–Haber cycle''' is an approach to analyze reaction [[energy|energies]]. It was named after and developed by the two [[Germans|German]] scientists [[Max Born]] and [[Fritz Haber]]. The cycle is concerned with the formation of an [[ionic compound]] from the reaction of a [[metal]] (often a [[Alkali metal|Group I]] or [[Alkaline earth metal|Group II]] element) with a [[halogen]].
If you need to speed up your PC then we have come to the appropriate spot. I will show we, today, five quick ways which you can dramatically better your computer's performance.<br><br>Before actually buying the software it is actually best to check on the companies which create the software. If you can find details found on the form of reputation every organization has, perhaps the risk of malicious programs may be reduced. Software from reputed businesses have helped me, plus other users, to create my PC run faster.. If the product description does not look good to we, refuses to include details regarding the software, refuses to include the scan functions, you need to go for another 1 that ensures you're paying for what we want.<br><br>With the Internet, the danger to your registry is more plus windows XP error messages may appear frequently. Why? The malicious wares like viruses, Trojans, spy-wares, ad wares, plus the like gets recorded too. Cookies are best examples. You reach protect passwords, plus stuff, proper? That is a easy illustration of the register functioning.<br><br>Windows errors can be caused by any amount of reasons, nevertheless there's almost usually one cause. There's a hidden piece of the system that is responsible for making 90% of all Windows mistakes, and it's called the 'registry'. This is the central database for your system and is where the computer shops all its program files plus settings. It's a important piece of Windows, which is should be capable to function. However, it's also one of the largest causes of problems on your PC.<br><br>Another thing you should check is whether or not the [http://bestregistrycleanerfix.com/tune-up-utilities tuneup utilities 2014] program you are considering has the ability to detect files plus programs that are advantageous. One of the registry cleaner programs you could try is RegCure. It is helpful for speeding up and cleaning up issues on your computer.<br><br>S/w associated error handling - If the blue screen bodily memory dump happens following the installation of s/w application or perhaps a driver it might be that there is system incompatibility. By booting into safe mode and removing the software you are able to swiftly fix this error. We can additionally try out a "program restore" to revert to an earlier state.<br><br>Perfect Optimizer is a advantageous Registry Product, updates consistently plus has many qualities. Despite its cost, there are that the update are really worthwhile. They provide plenty of help through telephone, send and forums. We may like to pay a visit to the free trial to check it out for oneself.<br><br>Before you purchase a whole new system; it is very time to receive the aged one cleaned up so you can begin getting more done online today! Visit our website below plus access the most reputable registry cleaner software accessible.
 
Born–Haber cycles are used primarily as a means of calculating lattice energies (or more precisely enthalpies<ref group="note">The difference between energy and enthalpy is very small and the two terms are interchanged freely in this article.</ref>) which cannot otherwise be measured directly. The [[lattice enthalpy]] is the [[enthalpy]] change involved in the formation of an ionic compound from gaseous ions. Some chemists define it as the energy to break the ionic compound into gaseous ions. The former definition is invariably [[exothermic]] and the latter is [[endothermic]]. A Born–Haber cycle applies [[Hess' Law]] to calculate the lattice enthalpy by comparing the [[standard enthalpy change of formation]] of the ionic compound (from the elements) to the enthalpy required to make gaseous ions from the [[Chemical element|elements]].
 
This latter calculation is complex. To make gaseous ions from elements it is necessary to atomise the elements (turn each into gaseous atoms) and then to ionise the atoms. If the element is normally a molecule then we first have to consider its [[bond dissociation enthalpy]] (see also [[bond energy]]). The energy required to remove one or more [[electron]]s to make a [[cation]] is a sum of successive [[ionization energy|ionization energies]]; for example the energy needed to form Mg<sup>2+</sup> is the first plus the second ionization energies of Mg. The energy changes when successive electrons are added to an atom to make it an [[anion]] are called the [[electron affinity|electron affinities]].  
 
The Born–Haber cycle applies only to fully ionic solids such as certain [[alkali halide]]s. Most compounds include covalent and ionic contributions to chemical bonding and to the lattice energy, which is represented by an extended Born-Haber thermodynamic cycle.<ref>H. Heinz and U. W. Suter ''Journal of Physical Chemistry B'' 2004, ''108'', 18341-18352.</ref> The extended Born–Haber cycle can be used to estimate the polarity and the atomic charges of polar compounds.
 
==Example: Formation of lithium fluoride==
[[File:BornHaberLiF.PNG|350px|thumb|right|Born–Haber cycle for the standard enthalpy change of formation of [[lithium fluoride]]. ΔH<sub>latt</sub> corresponds to U<sub>L</sub> in the text.]]
 
The enthalpy of formation of [[lithium fluoride]] (LiF) from its elements lithium and fluorine in their stable forms is modeled in five steps in the diagram:
 
# Enthalpy change of atomization enthalpy of lithium
# Ionization enthalpy of lithium
# Atomization enthalpy of fluorine
# Electron affinity of fluorine
# Lattice enthalpy
 
The same calculation applies for any metal other than lithium or any non-metal other than fluorine.
 
The sum of the energies for each step of the process must equal the enthalpy of formation of the metal and non-metal, <math>\Delta\text{H}_{\text{f}}</math>.
 
<math>\Delta\text{H}_{\text{f}} = \text{V} + \frac{1}{2}\text{B} + \text{IE}_{\text{M}} - \text{EA}_\text{X} + \text{U}_\text{L}</math>
 
*V is the [[enthalpy of sublimation]] for metal atoms (lithium)
*B is the bond energy (of F<sub>2</sub>). The coefficient 1/2 is used because the formation reaction is Li + 1/2 F<sub>2</sub> → LiF.
*<math>\text{IE}_{\text{M}}</math> is the [[ionization energy]] of the metal atom: <math>\text{M} + \text{IE}_\text{M} \to \text{M}^+ + \text{e}^-</math>
*<math>\text{EA}_\text{X}</math> is the [[electron affinity]] of non-metal atom X (fluorine)
*<math>\text{U}_\text{L}</math> is the [[lattice energy]] (defined as exothermic here)
 
The net enthalpy of formation and the first four of the five energies can be determined experimentally, but the lattice energy cannot be measured directly. Instead, the lattice energy is calculated by subtracting the other four energies in the Born–Haber cycle from the net enthalpy of formation.<ref>Moore, Stanitski, and Jurs. ''Chemistry: The Molecular Science.'' 3rd edition. 2008.  ISBN 0-495-10521-X. pages 320-321.</ref>
 
The word '''cycle''' refers to the fact that one can also equate to zero the total enthalpy change for a cyclic process, starting and ending with LiF(s) in the example. This leads to
<math> 0 = - \Delta\text{H}_{\text{f}} + \text{V} + \frac{1}{2}\text{B} + \text{IE}_{\text{M}} - \text{EA}_\text{X} + \text{U}_\text{L}</math>
which is equivalent to the previous equation.
 
==See also==
*[[ionic crystal]]
*[[ionic compound]]
*[[ionic liquid]]s
 
==Notes==
{{reflist|group=note}}
 
==References==
{{reflist}}
 
==External links==
*[http://www.youtube.com/watch?v=FD85Hetrg1Q ChemGuy on the Born-Haber Cycle]
 
{{DEFAULTSORT:Born-Haber cycle}}
[[Category:Solid-state chemistry]]
[[Category:Thermochemistry]]

Latest revision as of 14:44, 9 January 2015

If you need to speed up your PC then we have come to the appropriate spot. I will show we, today, five quick ways which you can dramatically better your computer's performance.

Before actually buying the software it is actually best to check on the companies which create the software. If you can find details found on the form of reputation every organization has, perhaps the risk of malicious programs may be reduced. Software from reputed businesses have helped me, plus other users, to create my PC run faster.. If the product description does not look good to we, refuses to include details regarding the software, refuses to include the scan functions, you need to go for another 1 that ensures you're paying for what we want.

With the Internet, the danger to your registry is more plus windows XP error messages may appear frequently. Why? The malicious wares like viruses, Trojans, spy-wares, ad wares, plus the like gets recorded too. Cookies are best examples. You reach protect passwords, plus stuff, proper? That is a easy illustration of the register functioning.

Windows errors can be caused by any amount of reasons, nevertheless there's almost usually one cause. There's a hidden piece of the system that is responsible for making 90% of all Windows mistakes, and it's called the 'registry'. This is the central database for your system and is where the computer shops all its program files plus settings. It's a important piece of Windows, which is should be capable to function. However, it's also one of the largest causes of problems on your PC.

Another thing you should check is whether or not the tuneup utilities 2014 program you are considering has the ability to detect files plus programs that are advantageous. One of the registry cleaner programs you could try is RegCure. It is helpful for speeding up and cleaning up issues on your computer.

S/w associated error handling - If the blue screen bodily memory dump happens following the installation of s/w application or perhaps a driver it might be that there is system incompatibility. By booting into safe mode and removing the software you are able to swiftly fix this error. We can additionally try out a "program restore" to revert to an earlier state.

Perfect Optimizer is a advantageous Registry Product, updates consistently plus has many qualities. Despite its cost, there are that the update are really worthwhile. They provide plenty of help through telephone, send and forums. We may like to pay a visit to the free trial to check it out for oneself.

Before you purchase a whole new system; it is very time to receive the aged one cleaned up so you can begin getting more done online today! Visit our website below plus access the most reputable registry cleaner software accessible.

Retrieved from "https://en.formulasearchengine.com/index.php?title=Divisibility_rule&oldid=235593"