Help identifying compound

[The_simpsons]

So i have a unknown chemical compound that is a white powder, very soluble in water (polar). But it doesn't conduct electricity in solution at all so i can probably exclude it's ionic. Also, when you heat it up in a bunsenburner it doesn't melt or combust, it stays pretty much the same, a stable powder. pH seemed kinda neutral in solution.

 

Does anybody have any idea how i can further test for which compound it is? First it seemed like a carbohydrate but since it doesn't melt or combust after prolonged heating i doubt it. Any ideas of what it might be or any new tests i can make to help identify it?

[Darkblade48]

Do you have a melting point apparatus? Everything eventually melts at some point

 

Of course, other identification methods are possible, but it all depends on the type of equipment you have access to.

[YT2095]

some of this doesn`t quite seem right?

 

reading it at 1`st you`de think Sugar, but then that Does burn!

when you mention the ph "pH seemed kinda neutral in solution. "

that doesn`t sound Very sure?

 

I`m wondering if the soln was slightly Basic perhaps and the powder was Sodium Silicate (Waterglass).

 

not too sure on it`s conductivity though?

 

I honestly cannot think of Anything Chemical that would respond in the way you`ve stated.

have you tried to see How soluble it is in a given quantity of water, and have you tried looking at Crystals of this to get an idea of it`s Molecular shape?

[The_simpsons]

Well i have acess to a high school chem lab, and the project was to identify an unknown solution in my current chemistry course.

 

Today though i found out it was a actually a salt, just a big salt, so it was harder to get a reading with a dip electrode, but with higher concentration it worked. It also gave a strong precipitation with Ba2+, so it's possibly a sulphate or a chromate. So im right on track again. Prepared the salt with several metals and im gonna see next week if the metal ion off the salt change place with the less noble metal.

[YT2095]

and it didn`t Conduct????

[The_simpsons]

It conducted after we added a higher concentration. If it was a bigger ionic compound than, say sodium chloride, which we compared conductivity with, we figured we needed more of the salt. After 2-3 times more of the unknown salt in relation to sodium chloride, it gave a similar conductivity as the NaCl-solution .

[YT2095]

Hmmm... I`m thinking it`s a sulphate also, maybe Magnesium Sulphate for instance.

 

not Chrome as most all are Colored (and they probably wouldn`t let you use that anyway).

 

add a little NaOH soln to it, you should also get a white ppt if it`s an MG salt.

[NeonBlack]

Why don't you try a flame test, or even a better if you have access, a spectrometer? (I think that's what they call it- the thing that lets you see how much light it absorbs)

[nitroglycol]

Hmmm... I`m thinking it`s a sulphate also, maybe Magnesium Sulphate for instance.

 

not Chrome as most all are Colored (and they probably wouldn`t let you use that anyway).

 

add a little NaOH soln to it, you should also get a white ppt if it`s an MG salt.

 

Could be magnesium sulphate, but it could also be zinc sulphate or something else. NeonBlack's suggestion of a flame test is a good idea.

[YT2095]

I will agree with you on this point, but Only because the Conductivity test wasn`t performed correctly.

 

Mg will not plate out, Zn will!

 

either way, the PPT when dried and heated will determine the Zn from the Mg, because Zinc oxide turns slightly Yellow above a certain temp