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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: aft on March 23, 2006, 08:49:08 PM

Title: state of matter for these ionic compunds
Post by: aft on March 23, 2006, 08:49:08 PM
are these compunds (aq) or (s) or (g) ??

Ba(OH)2

BaI2

FeI2

thanks for your *delete me*!
Title: Re:state of matter for these ionic compunds
Post by: Mitch on March 23, 2006, 08:53:15 PM
They look like solids. But you an use the MSDS blocks to your lower left to make sure. :)
Title: Re:state of matter for these ionic compunds
Post by: aft on March 23, 2006, 10:24:59 PM
jus wondering...how'd u determine they were solids by looking..?  
Title: Re:state of matter for these ionic compunds
Post by: mike on March 23, 2006, 10:31:22 PM
Almost all ionic compounds are solids (s)

Many of them dissolve in water to become aqueous ions, for example table salt NaCl (sodium chloride) is a solid (white crystaline solid you have probably had on fries etc). So NaCl(s) is a solid at room temperature, when you put it in water however it becomes sodium ions Na+(aq) and chloride ions Cl-(aq).

Many gases are covalent compounds and not ionic, for example O2 and N2.

Often the state that a compound is in will be determined by things like temperature or pressure (or both)
Title: Re:state of matter for these ionic compunds
Post by: aft on March 23, 2006, 11:19:22 PM
well, in the sense of this reaction:

FeSO4 (aq) + 2KI (aq) --> FeI2 + K2SO4

would FeI2 still be a solid or would it be (aq)?
 
Title: Re:state of matter for these ionic compunds
Post by: mike on March 23, 2006, 11:33:06 PM
Presuming that this is in water:

K2SO4 is soluble 24.1g per 100mL

and

FeI2 is soluble in cold and hot water.

So most probably it would be (aq) FeI2(aq)

You can look up solubilities of most compounds, I looked in the CRC handbook for these. Maybe some of the search boxes on the left might help too. :)
Title: Re:state of matter for these ionic compunds
Post by: aft on March 23, 2006, 11:57:59 PM
hmm....i c... its (aq) then....

i checked the boxes and they all tell me its a solid of sorts... but i guess its assuming that it isn't in solution....

anyways, thanks a bunch for your *delete me*!  :jump:
Title: Re:state of matter for these ionic compunds
Post by: AWK on March 24, 2006, 01:47:08 AM
Quote from: [AFT] on March 23, 2006, 08:49:08 PM
are these compunds (aq) or (s) or (g) ??

Ba(OH)2

BaI2

FeI2

thanks for your *delete me*!

It depends on temperature. At RT they are solids
Title: Re:state of matter for these ionic compunds
Post by: mike on March 24, 2006, 06:17:25 PM
Quote
It depends on temperature. At RT they are solids

Unless they are in water, as we already stated above.