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Subject: [DCHAS-L] CHAS Chat Recording available
Date: Friday, March 12, 2021 at 1:33:32 PM
Author: CHAS membership chair <membership**At_Symbol_Here**DCHAS.ORG> 		Next by Date:
Subject: Re: [DCHAS-L] Condensation of liquid oxygen in open Dewar flasks of liquid nitrogen
Date: Fri, 12 Mar 2021 13:00:21 -0600
Author: Harry Elston

From: Benjamin Ruekberg <bruekberg**At_Symbol_Here**URI.EDU>
Subject: Re: [DCHAS-L] CHAS Chat Recording available
Date: Fri, 12 Mar 2021 13:53:41 -0500
Reply-To: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**Princeton.EDU>
Message-ID: CAJug0OxhkEmnSLfyreAu-8xU0y4E=0uLSZKiY2EJ6QMQuF5vyg**At_Symbol_Here**mail.gmail.com
In-Reply-To <827DFA9A-736B-4167-8320-667A2F9E9EC5**At_Symbol_Here**dchas.org>


I may be a nervous Nelly, but, with all due respect, I am a bit less optimistic than other replies have indicated.

Assume you have a Dewar of liquid nitrogen. The walls above the liquid nitrogen are good insulators, so one might expect that the nitrogen vapor is not far above the boiling point of 77 K. This would still be cold enough to condense oxygen (bp 90 K). And where is the condensed oxygen apt to go? Down.

Does one ever see ice upon the lip of a nitrogen Dewar? When water vapor condenses to ice, it doesn't travel very far.. Considering the vapor pressure of water and the fact that relative humidity represents the fraction of that vapor pressure of water present, and that this is much lower than the partial pressure of oxygen in the atmosphere, I would not bet the farm on oxygen's not condensing into the liquid nitrogen.

Thank you very much,

Ben

Virus-free. www.avast.com

On Fri, Mar 12, 2021 at 1:34 PM CHAS membership chair <membership**At_Symbol_Here**dchas.org> wrote:
The recording from yesterday's CHAS chat on Quality Data for Safer Experiments is now available on the DCHAS web site at
https://urldefense.proofpoint.com/v2/url?u=http-3A__dchas.org_2021_03_11_quality-2Ddata-2Dfor-2Dsafer-2Dexperiments_&d=DwIDaQ&c=dWz0sRZOjEnYSN4E4J0dug&r=uBOqtwFxTSCgKsbxHVHLQwvlW8ezbrw-7uNwvE5fqq0&m=6G4EQttDYw_280lwmKlfrtjkCAqL0bAA4eY9eW5woG4&s=x9hNK57YY6MH0t8DPK6WlFJCHQEvxyWkTYXPaWVenCc&e= This page also lists the web site that were mentioned in the discussion and some of the comments that appeared in the chat.

I found the discussion very interesting and many helpful ideas and resources were discussed. My thanks to everyone who took the time to participate in this event!

- Ralph

Ralph Stuart, CIH, CCHO
Membership Chair
American Chemical Society Division of Chemical Health and Safety
membership**At_Symbol_Here**dchas.org

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