I guess I should have been more specific. The department has been doing this demo for YEARS and they wanted me to set up the aparatus when I noticed a hairline fracture in the erlenmeyer. I'm trying to replace it. The whole set up is safe, that's not the problem. The problem is that it's  NYC university (CUNY) and the budget isn't what it used to be.

Thanks all for your concern but I'm really just asking about where you would go for glassware. I have already asked the chemistry department but they don't have what I'm looking for.

S

On Fri, Sep 13, 2013 at 6:00 AM, DAVID KATZ <dakatz45**At_Symbol_Here**msn.com> wrote:

Instead of purchasing a large filter flask at a high price, just use a video camera to project the live demonstration, in  a 250-mL or 500-mL filter flask, on a large screen in the lecture hall.  Check the filter flask, before use, for scratches or chips and use proper clamping and safety shielding of the apparatus.

 

As an alternative, use a bell jar and vacuum apparatus to do this demonstration in a beaker.  Again, project the demonstration on a large screen.  Safety shields are still recommended.  Protect your vacuum pump from the water vapors with a trap.

 

You probably want to use room temperature water for the demonstration, but you can get reasonable results with warm water in the filter flask using a good water aspirator.

 

I also use large 140-mL or 100-mL plastic syringes (never glass) with end caps, containing a small amount of water, which can be passed around the room so students can repeat the demonstration at their seats.  Occasionally, a student will pull the plunger completely out of the syringe splashing the water, but you can minimize that by cautioning the students in advance.

 

David  

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----- Original Message -----

From: Samantha D

To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU

Sent: Thursday, September 12, 2013 8:09 AM

Subject: Re: [DCHAS-L] 4L filter flasks

Hi all,

I'm looking for a 4L filter flask for a demo but they all seem to be $150-$250. We are creating a vacuum in order to boil water. It needs to be that big because of the size of the lecture hall. Does anyone have a good website to turn to for glassware like this?

Thank you,

Sam

On Thu, Sep 12, 2013 at 10:56 AM, Samantha D <samantha.dannenberg**At_Symbol_Here**gmail.com> wrote:

Hi all,

I'm looking for a 4L filter flask for a demo but they all seem to be $150-$250. We are creating a vacuum in order to boil water. It needs to be that big because of the size of the lecture hall. Does anyone have a good website to turn to for glassware like this?

Thank you,

Sam

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