Sodium Nitrate Bond
Date: October 2006
What kind of bond is sodium nitrate? I know that Na
( sodium) is a non-metal and that NO3(nitrate) is an ionic bond, so
when they are together what is the name for that bond?
Sodium actually is a metal, and it has a charge of positive one. Nitrate is
a polyatomic ion, meaning atoms of oxygen and nitrogen are covalently bonded
to each other (bonding due to the sharing of electrons), and the nitrate ion
has a charge of (-1). If you look up nitrate on Wikipedia you can see a
picture of the structure. When things that have full opposite charges on
them bind due to the charge on each one, it is an ionic bond, so the bond
formed between sodium (+1) and the nitrate ion (-1) is ionic.
Stanford Department of Chemistry
Sodium is a metal (not a nonmetal),
and it forms the +1 cation in
most cases. In this situation it combines with the
-1 charged nitrate ion, NO3-, to form NaNO3. This
is an ionic substance and the bonds between sodium
cations and nitrate anions are ionic bonds.
Best wishes, and keep asking questions
You can easily determine what any bond type is if you have access to
a periodic table that contains the electronegativity of each
atom. First, though, sodium IS a metal and NO3 contains three N-O
covalent bonds. A bond is simply the term used when two atoms share
electrons. If you subtract the electronegativity of each of the two
bonding atoms the resulting number will tell you what type of bond
you have. If the number is between 0 and 1.51, then you have a
covalent bond (a relatively equal or completely equal sharing of
electrons). If your number is greater than 1.51 then you have an
ionic bond (unequal sharing of electrons). Remember that ionic
bonds produce ions, meaning that the electrons involved in the bond
reside on one atom the vast majority of the time, whereas electrons
in a covalent bond spend closer to 50/50 time around each atom.
To determine what types of bonds NaNO3 contains, you first must draw
out the complete structure. You can find the structure at
www.chemfinder.com if you are unsure how to draw it. The structure
contains two N-O single bonds, and N=O double bond and an Na-O
bond. Electronegativities are as follows: N = 3.0, O = 3.5 and Na
= 0.9. N-O bonds have an electronegativity difference of 3.5 - 3.0
= 0.5, which is less than 1.51 and means that the bond is
covalent. O-Na bonds have an electronegativity difference of 3.5 -
0.9 = 2.6, which is higher than 1.51 and so is an ionic
bond. Remember that ionic bonds produce ions, and in the structure
you have a positively charged sodium and a negatively charged oxygen.
Sodium nitrate is an ionic solid. However, in contrast to what you
wrote, the bonding within nitrate is covalent, and sodium is a metal.
Department of Physics and Astronomy
University of Wyoming
First, sodium (Na) is considered a metal (not a non-metal). N and O
are considered non-metals. But these are mostly irrelevant to the
consideration of what bond occurs between Na and the nitrate ion.
Notice that in NaNO3 we consider that the Na is a cation and the
nitrate as an anion. This means that we expect Na to be (1+) and the
nitrate ion to be (1-). As such, when the two come together they
form a bond that is a result of of the electrostatic attraction
coming from full charges - which is what an ionic bond is by definition.
Greg (Roberto Gregorius)
You have made an incorrect assumption (definition). Sodium (Na) is a metal
and readily donates a single electron (a primary property of a metal) to
form Na(+1). The bonds between the nitrogen and the oxygens is approximately
covalent. The bonding between the Na(+1) and the (NO3(-1)) is essentially an
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