Right, i understand that acidity properties increase moving from left to right on the periodic table, and that this is due to the electronegativity increase, making non metal oxides Covalent and metal oxides ionic. But why does the bonding structure effect the acidity? Or am i on the complete wrong track
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Acidicty/Basicity Of Oxides (1 Viewer)
- Thread starter Robbo_m8
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Slidey
But pieces of what?
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Acidic oxides are covalent. Most metals don't form covalent bonds, but form ionic bonds. Basic oxides are ionic.
Why do covalent elements and molecules form acidic oxides?
Let's look at it this way:
In order for an oxide to be acidic, it must react with water to form an acid, or neutralise a base to form a salt.
If acidic oxides were ionic, then since oxygen will form negative ions or neutral molecules, the other part must form positive ions. But in a base, the ion given to from salt is also positive - two positive ions (like a metal) will not form a salt, so the acidic oxide cannot be ionic, leaving only covalent.
Why do covalent elements and molecules form acidic oxides?
Let's look at it this way:
In order for an oxide to be acidic, it must react with water to form an acid, or neutralise a base to form a salt.
If acidic oxides were ionic, then since oxygen will form negative ions or neutral molecules, the other part must form positive ions. But in a base, the ion given to from salt is also positive - two positive ions (like a metal) will not form a salt, so the acidic oxide cannot be ionic, leaving only covalent.
it has to do with the electronegativity as u have said... oxides usually have the general formula:
R - O - H
when R's a metal, it has less electro negativity... so the electrons are more drawn to the oxygen, hence weakenling the R - O bond, making it more easily broken and forming a OH - ion (base)
when R's tending non metal, it has high electronegativity... inaddition to be drawn towards oxygen, the electrons are also drawn towards R, hence the O - H bond is further weaken... hence O-H are most likely to be broken, forming H + ions (acid)
edit: the type of bonds are mainly due to the electronegativity of the atoms... so acidity of oxides and type of bonds are more like two independent events caused by the same cause...
R - O - H
when R's a metal, it has less electro negativity... so the electrons are more drawn to the oxygen, hence weakenling the R - O bond, making it more easily broken and forming a OH - ion (base)
when R's tending non metal, it has high electronegativity... inaddition to be drawn towards oxygen, the electrons are also drawn towards R, hence the O - H bond is further weaken... hence O-H are most likely to be broken, forming H + ions (acid)
edit: the type of bonds are mainly due to the electronegativity of the atoms... so acidity of oxides and type of bonds are more like two independent events caused by the same cause...