TBR Bonding?

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Sammy1024

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What is it called when something splits? Is it called dissociation?

Ex: HCl -> H+ + Cl-
Ex: NaCl -> Na+ + Cl-

It's been bugging me since yesterday but I didn't know where to really look for it since it's kind of random.

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It's called heterolytic bond cleavage when you break something up and the divorce settlement does not allocate electrons equally between the two newly unweds.
 
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I wish I could look into your mind for all my MCAT question when I take it! lol!
 
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What is it called when something splits? Is it called dissociation?

Ex: HCl -> H+ + Cl-
Ex: NaCl -> Na+ + Cl-

Not to dig up an already answered thread, but your examples seems more like Decomposition reactions (chem term?). Decomposition seems more spontaneous than cleavage, but outside of that it probably depends on the lexicon of your field.
[edit] Could also be called an "ionization reaction" for those examples?
http://en.wikipedia.org/wiki/Chemical_decomposition

Ripped From the following website:
http://misterguch.brinkster.net/6typesofchemicalrxn.html

3) Decomposition: A decomposition reaction is the opposite of a synthesis reaction - a complex molecule breaks down to make simpler ones. These reactions come in the general form:
AB ---> A + B
One example of a decomposition reaction is the electrolysis of water to make oxygen and hydrogen gas:
2 H2O ---> 2 H2 + O2
[Edit] Shortened post.
 
Last edited:
Not to dig up an already answered thread, but your examples seems more like Decomposition reactions (chem term?). Decomposition seems more spontaneous than cleavage, but outside of that it probably depends on the lexicon of your field.
[edit] Could also be called an "ionization reaction" for those examples?
http://en.wikipedia.org/wiki/Chemical_decomposition

Ripped From the following website:
http://misterguch.brinkster.net/6typesofchemicalrxn.html

All chemical reactions can be placed into one of six categories. Here they are, in no particular order:

1) Combustion: A combustion reaction is when oxygen combines with another compound to form water and carbon dioxide. These reactions are exothermic, meaning they produce heat. An example of this kind of reaction is the burning of napthalene:

C10H8 + 12 O2 ---> 10 CO2 + 4 H2O

2) Synthesis: A synthesis reaction is when two or more simple compounds combine to form a more complicated one. These reactions come in the general form of:

A + B ---> AB

One example of a synthesis reaction is the combination of iron and sulfur to form iron (II) sulfide:

8 Fe + S8 ---> 8 FeS

3) Decomposition: A decomposition reaction is the opposite of a synthesis reaction - a complex molecule breaks down to make simpler ones. These reactions come in the general form:

AB ---> A + B

One example of a decomposition reaction is the electrolysis of water to make oxygen and hydrogen gas:

2 H2O ---> 2 H2 + O2

4) Single displacement: This is when one element trades places with another element in a compound. These reactions come in the general form of:

A + BC ---> AC + B

One example of a single displacement reaction is when magnesium replaces hydrogen in water to make magnesium hydroxide and hydrogen gas:

Mg + 2 H2O ---> Mg(OH)2 + H2

5) Double displacement: This is when the anions and cations of two different molecules switch places, forming two entirely different compounds. These reactions are in the general form:

AB + CD ---> AD + CB

One example of a double displacement reaction is the reaction of lead (II) nitrate with potassium iodide to form lead (II) iodide and potassium nitrate:

Pb(NO3)2 + 2 KI ---> PbI2 + 2 KNO3

6) Acid-base: This is a special kind of double displacement reaction that takes place when an acid and base react with each other. The H+ ion in the acid reacts with the OH- ion in the base, causing the formation of water. Generally, the product of this reaction is some ionic salt and water:

HA + BOH ---> H2O + BA

One example of an acid-base reaction is the reaction of hydrobromic acid (HBr) with sodium hydroxide:

HBr + NaOH ---> NaBr + H2O

This is the most useless list I've ever saw. This is for high schoolers on AP exams. I have never had to classify a reaction using any of the terms on this list save "combustion" and "acid-base" and even the latter is too broad to be of any use. Lewis acid/base reaction? Bronsted-Lowry acid/base reaction?

The OP's reaction represents 1) heterolytic bond cleavage and 2) ionization if you prefer. Note that it should be obvious that heterolytic bond cleavage of a molecule should produce ions.
 
This is the most useless list I've ever saw. This is for high schoolers on AP exams. I have never had to classify a reaction using any of the terms on this list save "combustion" and "acid-base" and even the latter is too broad to be of any use. Lewis acid/base reaction? Bronsted-Lowry acid/base reaction?

The OP's reaction represents 1) heterolytic bond cleavage and 2) ionization if you prefer. Note that it should be obvious that heterolytic bond cleavage of a molecule should produce ions.

The OP question was: "What is it called when something splits?"
Two examples were provided but there are many ways to describe how something can split.
If the question was "What are these reactions called?" I wouldn't link extra info.

Also i'm not sure if you noticed but the second example (NaCl) is ionic and has very little covalent character. So calling it "heterolytic bond cleavage" would be quite a stretch as the electrons weren't really 'shared' to begin with.
"Dissociation" of the ionic nature of the crystal lattice structure would be a more accurate name for that example.


...Honestly i felt like you were going to challenge that statement so I went to the source. :D
IUPAC Compendium of Chemical Terminology - the Gold Book ==> http://goldbook.iupac.org/index.html

Their definition...
heterolysis (heterolytic):
"The cleavage of a covalent bond so that both bonding electrons remain with one of the two fragments between which the bond is broken."


Basically not everything is as simple as you were implying. =P
Or maybe IUPAC is wrong, who knows.
You could try and convince me that NaCl is covalent, but yeah... ;)

 
You're right, for the second example, that's dissociation or ionization, but it was referring to the first example in my last post.

Or maybe IUPAC is wrong, who knows.
You could try and convince me that NaCl is covalent, but yeah... ;)

I'm sure you'd fall for a lot of other unicorns ;).
 
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