What is the Identity of the Unknown Liquid Used in a Dumas Bulb Experiment?

  • Thread starter Thread starter yellowcakepie
  • Start date Start date
  • Tags Tags
    Identity Liquid
Click For Summary

Discussion Overview

The discussion revolves around identifying an unknown clear liquid used in a Dumas bulb experiment aimed at determining its molar mass. Participants explore the characteristics of the liquid based on experimental results and safety considerations.

Discussion Character

  • Exploratory
  • Debate/contested
  • Homework-related

Main Points Raised

  • One participant reports a mean molar mass of 38.1 g/mol with a large confidence interval, noting issues with the experimental trials.
  • The participant describes the liquid as clear, safe to inhale in vapor form, lacking a distinct smell, and having a boiling point below 100 degrees C.
  • Another participant questions the claim of the liquid not having a distinct smell, suggesting that both ethanol and methanol have characteristic odors.
  • A different participant argues that methanol is not significantly more poisonous than other common solvents, stating that inhaling it is unlikely to cause harm.
  • The original poster expresses uncertainty between identifying the liquid as ethanol or methanol, citing safety concerns regarding methanol's toxicity in vapor form.

Areas of Agreement / Disagreement

Participants express differing views on the safety and characteristics of methanol and ethanol, with no consensus reached on the identity of the unknown liquid.

Contextual Notes

The discussion includes uncertainties regarding the identification of the liquid based on its physical properties and safety implications, as well as the reliability of the experimental results due to limited trials.

yellowcakepie
I performed a laboratory experiment using a Dumas bulb to find the molar mass of an unknown, clear liquid in order to identify it. The Dumas bulb was submerged in a beaker filled with water (with the tip out of the water) and the water was boiled to evaporate the sample.

I eventually got a result with 38.1 g/mol as the mean, with a huge confidence interval (at 95%) of +- 18.1 g/mol. This is because I screwed up my 3rd trial so I could only use my first 2. I got results of 36.72, 39.56, and 49.11 g/mol.

I need help identifying this liquid.

The liquid is clear, safe to inhale in vapor form (I'm still alive), does not have a distinct smell, has a boiling point lower than 100 degrees C, and is not "an exotic compound".

Edit: I'm now deciding between ethanol and methanol. I'm hearing that methanol is poisonous in vapor form, so I think it may be ethanol.
 
Last edited by a moderator:
Physics news on Phys.org
This appears to be lab homework, so moving the thread to homework section. No template.
 
yellowcakepie said:
does not have a distinct smell

I'm now deciding between ethanol and methanol. I'm hearing that methanol is poisonous in vapor form, so I think it may be ethanol.

These alcohols do have a quite characteristic smell.
 
Methanol isn’t really any more poisonous than other common solvents. Of course, like most common solvents, if you drink it, that’s bad news, but simply smelling it is very unlikely to hurt you.
 

Similar threads

Replies
7
Views
2K
Replies
3
Views
14K
  • · Replies 7 ·
Replies
7
Views
3K
Replies
2
Views
3K
  • · Replies 3 ·
Replies
3
Views
10K
Replies
1
Views
3K
Replies
5
Views
5K