Finding The Identity of Unknowns

  • Thread starter Thread starter don123
  • Start date Start date
  • Tags Tags
    Identity Unknowns
AI Thread Summary
To identify unknown substances in a chemistry class, heating the liquids to determine their boiling points is a suggested method, as it can help narrow down possibilities using reference materials. Other effective techniques include conducting density measurements and solubility tests to observe how the unknowns interact with solvents. While color tests can be useful, they are most effective when combined with other methods. The discussion emphasizes the importance of a systematic approach to gather qualitative data about the substances. Overall, a combination of boiling point, density, and solubility tests is recommended for accurate identification.
don123
Messages
6
Reaction score
0
For my chem class my teacher is going to give us 2 unknowns and we have to find out their identity. How would you do this?

I figured that you would heat the liquids to figure out their boiling point and then look in the book (she'll let us use the books) to figure out the substaNce.

I could also do the color test lab but I don't think that it is very effective.

BTW I posted this in Chem section and didn't get respons so I figured I'd try here.
 
Physics news on Phys.org
don123 said:
For my chem class my teacher is going to give us 2 unknowns and we have to find out their identity. How would you do this?

I figured that you would heat the liquids to figure out their boiling point and then look in the book (she'll let us use the books) to figure out the substaNce.

I could also do the color test lab but I don't think that it is very effective.

BTW I posted this in Chem section and didn't get respons so I figured I'd try here.

Hello Don.
Surely you must have some general guidelines and have at least some idea what it is right? Generally you'll have some qualitative scheme to "narrow down" the possible candidates. Have you been given this? Is is both two liquids? Both organic? Polar, non-polar? Volatile? I don't know about the heating up part. You know, you can just wave your hand over it carefully to get just a tiny and I mean tiny wiff of it. You know basic rule of Chemistry is NOT to put your nose to it right? Well, I don't know what you know. Smells like alcohol, we're on our way.

Edit: I think color test are effective if done in a methodical way and used with other evidence.
 
Last edited:
don123 said:
For my chem class my teacher is going to give us 2 unknowns and we have to find out their identity. How would you do this?

I figured that you would heat the liquids to figure out their boiling point and then look in the book (she'll let us use the books) to figure out the substaNce.

I could also do the color test lab but I don't think that it is very effective.

BTW I posted this in Chem section and didn't get respons so I figured I'd try here.
Boiling point is one good indicator. The density is another. You can also do solubility tests (is the unknown liquid dissolved and completely mixed with the solvent or do they form layers, etc.). In fact, I imagine that either your textbook or lab book has a table that lists all three characteristics (boiling point, density, & a solubility chart). If not, I'm sure the lab has a reference that does (the CRC book is a good reference - even if I can't remember it's full name, I think it normally has a dark red cover :smile: ).
 
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
Back
Top