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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: Susie_Carlsom on July 24, 2007, 03:41:07 PM

Title: Chemistry Formula checked.
Post by: Susie_Carlsom on July 24, 2007, 03:41:07 PM
Engrium sulfate has the formula, En2(SO4)3, while sodium nortonite has the formula Na2NtO3.  Based on these names and formulas, what would you expect for the formula of engrium nortonate?


I came up with En2NtO3  Does this sound okay?
Title: Re: Chemistry Formula checked.
Post by: DevaDevil on July 24, 2007, 03:45:57 PM
remember, sodium has the formal charge 1+ in ionic compounds, where sulfate has the formal charge 2-

What does this lead to for the formal charges of En and NtO3 ?
Title: Re: Chemistry Formula checked.
Post by: Susie_Carlsom on July 24, 2007, 03:52:36 PM
Would it cancel out the two?
Title: Re: Chemistry Formula checked.
Post by: sdekivit on July 24, 2007, 04:34:34 PM
based on the formal charge discussed by devadevil you must combine En and NtO3 to 'create' an uncharged molecule.
Title: Re: Chemistry Formula checked.
Post by: Susie_Carlsom on July 24, 2007, 07:16:36 PM
Im Confused  ???
Title: Re: Chemistry Formula checked.
Post by: Yggdrasil on July 25, 2007, 12:04:27 AM
For ionic compounds, you will know the proportions in which they combine based solely on charge.  Consider the example of sodium sulfate.  Sodium ions, since they come from a group I metal, have a charge of +1.  Sulfate ions have a charge of -2 (this is something you will probably just have to memorize).  For sodium (Na+) and sulfate (SO42-) to form an ionic compound, the compound must have no net charge.  For this to happen, sodium sulfate must have the formula Na2SO4.  The two sodium ion contribute a +2 charge to balance out the -2 charge of the sulfate.

Now consider aluminum oxide.  Aluminum ions have a +3 charge.  Oxygen ions have a -2 charge.  In order for them to balance, aluminum oxide must have a formula of Al2O3.  The two aluminum ions contribute a 2x(+3) = +6 charge and the 3 oxygen ions contribute a 3x(-2) = -6 charge, giving aluminum oxide an overall charge of zero.

This principle can also be used to figure out the charge of unknown ions.  Consider a particular form of tin chloride (SnCl2).  Since we know that chlorine has a -1 charge (based on its position in the periodic table), the tin must have a +2 charge to balance out the -2 charge contributed by the two chloride ions.
Title: Re: Chemistry Formula checked.
Post by: AWK on July 25, 2007, 12:59:00 AM
Engrium sulfate has the formula, En2(SO4)3, while sodium nortonite has the formula Na2NtO3.  Based on these names and formulas, what would you expect for the formula of engrium nortonate?


I came up with En2NtO3  Does this sound okay?
In analogy, balance double exchange reaction
Fe2(SO4)3 + Na2CO3 =
Title: Re: Chemistry Formula checked.
Post by: Susie_Carlsom on July 25, 2007, 08:12:57 AM
Okay so I end up with En2(NtO3)3 ??

Title: Re: Chemistry Formula checked.
Post by: DevaDevil on July 25, 2007, 12:49:38 PM
exactly
Title: Re: Chemistry Formula checked.
Post by: Susie_Carlsom on July 25, 2007, 04:07:04 PM
Thanks alot for your assistance!