Finding The Identity of Unknowns

In summary, the conversation discusses different methods for identifying unknown substances in a chemistry class. These methods include using boiling point, solubility tests, and color tests. The conversation also mentions the importance of following safety guidelines and using references such as textbooks or lab books.
  • #1
don123
6
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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.
 
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  • #2
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.
 
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  • #3
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: ).
 

FAQ: Finding The Identity of Unknowns

1. What is the purpose of finding the identity of unknowns in scientific research?

The main purpose of identifying unknowns in scientific research is to gain a better understanding of the properties and behaviors of various substances. This information can then be used to make predictions, develop new technologies, and further scientific knowledge in a particular field.

2. How do scientists determine the identity of unknowns?

Scientists use a variety of techniques and instruments to determine the identity of unknowns, such as spectroscopy, chromatography, and mass spectrometry. These methods involve analyzing the physical and chemical properties of a substance and comparing them to known standards or databases.

3. What are some challenges that scientists face when trying to identify unknowns?

One of the main challenges in identifying unknowns is the availability of reference materials and databases. If there is no existing data for a particular substance, scientists may have to develop their own methods or standards. Additionally, samples may be contaminated or impure, making it difficult to obtain accurate results.

4. Why is it important to correctly identify unknowns in scientific research?

Incorrectly identifying unknowns can lead to inaccurate conclusions and hinder the progress of scientific research. It is crucial to have a clear understanding of the substances being studied in order to make reliable predictions and draw valid conclusions.

5. What are some real-world applications of finding the identity of unknowns?

Finding the identity of unknowns has many practical applications in various industries, such as pharmaceuticals, food and beverage, environmental testing, and forensic science. It can also be used in everyday life, such as determining the purity of household products or identifying unknown substances found at a crime scene.

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