Friday, April 16, 2010

What properties are linked to ionic compounds and molecular compounds?

what properties are linked to ionic compounds and molecular compounds?

What properties are linked to ionic compounds and molecular compounds?
Ionic Bonding:


All ionic bonds deal with a metal and a non-metal. There may be more than one non-metal in the bond, which are also known as polyatomic ions.


Bonding in an ionic bond only occurs when there is attraction of positive and negative ions in a three-dimensional array. When the bond is formed, there are only enough electrons transferred so that each ion has a filled outer energy level. The valence electrons are the electrons that get transferred back and forth between the ionic bond.


Some characteristics that many ionic bonds share are that they’re usually white, they’re brittle solids which melt at high temperatures, their molten form or aqueous solutions contain mobile positive and negative ions which conduct electricity very well. Ionic compounds dissolve easily in water and other polar solvents.


Naming the metallic part of an ionic bond is the same as the metallic atom. The non-metallic ion is changed to the ending of –ide. Almost always, metallic names are stated before non-metallic.


Two common ionic bonds that humans are benefited from are calcium chloride and calcium oxide. When there is excess ice and snow on the roads, calcium chloride is used to clear the roads. To make components of cement and fertilizer, you need calcium oxide to provide high amounts of nutrients.


Ionic bonds are a type of chemical bond based on electrostatic forces between two oppositely-charged ions. Often ionic bonds form between metals and non-metals. In ordinary table salt, the bonds between the sodium and chlorine ions are ionic bonds. In ionic bond formation, a metal donates an electron, due to a low electronegativity to form a positive ion or cation. The non-metal atom has an electron configuration just short of a noble gas structure. They are electronegative, and so readily gain electrons to form negative ions or anions. The two or more ions are then attracted to each other by electrostatic forces. Such bonds are stronger than hydrogen bonds, but similar in strength to covalent bonds.











Ionic bonding occurs only if the overall energy change for the reaction is favourable when the bonded atoms have a lower energy than the free ones. The larger the resulting energy change the stronger the bond.





Pure ionic bonding is not known to exist. All ionic bonds have a degree of covalent bonding or metallic bonding. The larger the difference in electronegativity between two atoms the more ionic the bond. Ionic compounds conduct electricity when molten or in solution. They generally have a high melting point and tend to be soluble in water.











Covalent bonding is an intramolecular form of chemical bonding characterized by the sharing of one or more pairs of electrons between two species, producing a mutual attraction that holds the resultant molecule together. Atoms tend to share electrons in such a way that their outer electron shells are filled. Such bonds are always stronger than the intermolecular hydrogen bond and similar in strength to or stronger than the ionic bond.





Covalent bonding most frequently occurs between atoms with similar electronegativities. For this reason, non-metals tend to engage in covalent bonding more readily since metals have access to metallic bonding, where the easily-removed electrons are more free to roam about. For non-metals, liberating an electron is more difficult, so sharing is the only option when confronted with another species of similar electronegativity.





However, covalent bonding involving metals is particularly important, especially in industrial catalysis and process chemistry. Many polymerization techniques require catalysis involving metal-organic covalent bonds. In their more useful applications, metals often engage in more exotic covalent bonding, such as those between a metal and the σ bond of molecular hydrogen, or between a metal and the π bond of an alkane or alkene.














A molecule like sodium chloride is refered to as ionic because the electron pair rests entirely on one atom. At the other extreme is the covalent bond as in the hydrogen molecule. Molecules of this nature share electrons equally. Molecules are not confined to these two types, many molecular bonds are of varying degrees of these two extremes. Figure 3 is a hydrogen flouride model with a transparent electrostatic potential map displayed (An electrostatic potential map displays where the charges reside in a molecule--red is negative and blue is positive). In cases like this, the bond is intermediate with a clear "polarization" toward one of the elements. Bonds of this type are refered to as polar covalent bonds.
Reply:I appreciate the second answer.
Reply:Molecular compounds are generally made of 2 or more non metals. Held by a covalent bond (ie atoms are linked by sharing electrons) while Ionic compounds are made of atleast a metal %26amp; a non-metal. Bond is ionic implying transfer of electrons to resolve or partially resolve their seperate charge imbalance.





molecular cmpds have low boiling %26amp; melting points, can be solid, liquid or gas at room temp w/ low electrical conductivity unlike ionic compounds


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