Tuesday
September 30, 2014

Homework Help: Mixed melting point

Posted by Sheryl on Sunday, October 1, 2006 at 8:16pm.

Question: A compound melting at 134 degrees C was suspected to be either aspirin (mp 135C) or urea (mp 133C) Explain how you could determine whether one of these two suspected compounds was identical to the unknown compound without using any form of spectroscopy.

This seems the same type of problem as my other most recent posting. It seems that the identity could be determined by a mixed melting point procedure if you had aspirin and urea available. A narrow melting point range would verify the substance and eliminate the other.

Sheryl


That's right. Another solution would be odor. Most aspirin smells faintly of acetic acid, expecially in moist air. It hydrolyzes. Urea, with most air and hydrolysis, smells like NH3. Urea is a base, aspirin is an acid so that will distinguish them also. But the mixed melting point is the correct answer here since that is what you are studying.

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

Chemistry - A student who was isolating aspirin stopped the experiment after ...
org. chem. - A student who was isolating aspirin stopped the experiment after ...
chemistry - Say you have two substances, A and B. A has a melting point of 300 ...
Same substances? - Question: Two substances, A and B, have the same melting ...
Chemistry - Student in O-Chem Lab conducts a melting point experiment with an ...
chemistry - Pure acetylsalicylic acid has a melting point of 135.0 - 135.5 (...
Organic Chemistry - Melting Point Determinations between urea and trans-cinnamic...
organic chem/ melting pt lab - why does a soluble impurity reduce the melting ...
chemistry - Melting point experiment: how do i know the calibration curve? we ...
Organic Chemistry - Melting Point - You have an unknown with an observed melting...

Search
Members