RE: Normal solution

From:Jim at ProSciTech <jim@proscitech.com>

Some people may not be aware that a strong stock solution can be diluted 
whatever is required. So 2.0 N diluted 1+ 9 (H20) becomes a 0.2N solution. A 10 
N solution of NaOH (near saturated)lasts indefinitely, whereas a 1N solution 
contaminates with carbonates in time.

When making up NaOH solutions, a couple of other bits of lab practice should be 
remembered:
The reaction is strongly exothermic and the temptation to make the solution up 
in a volumetric glass flask should be resisted, since they tend to crack. Weigh 
the pellets into a conical flask, they can stand the heat better. Then add most 
of the water required and dissolve, perhaps with the aid of a stirring bar. 
After the solution is cooled transfer into a volumetric flask and make up to 
the exact quantity required.
Long term storage should be in a strong plastic bottle since concentrated 
 caustic attacks glass.

For some applications its important to have a carbonate free solution of NaOH 
(certainly for lead staining in electron microscopy), this requires some 
additional precautions, but that is another topic.
Cheers
Jim Darley
ProSciTech                 Microscopy PLUS
PO Box 111, Thuringowa  QLD  4817  Australia
Ph +61 7 4774 0370  Fax:+61 7 4789 2313  service@proscitech.com
Great microscopy catalogue, 500 Links, MSDS, User Notes
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On Thursday, March 01, 2001 8:00 AM, Lott, Robert [SMTP:Robert.Lott@bhsala.com] 
wrote:
> A 2N solution of NaOH contains two gram-equivalent weights of solute per
> liter of solution.  To determine the gram equiv. weight of NaOH, you simply
> add the molecular weights of Sodium-23, Oxygen-16, and Hydrogen-1 = 40.0
>
> 40.0 gm/1000.0 ml d-water = 1N
> 80.0 gm/1000.0 ml d-water = 2N
> 200.0 gm/1000.0 ml d-water = 5N
>
> -----Original Message-----
> From: Laurie Colbert [mailto:laurie.colbert@schs.com]
> Sent: Wednesday, February 28, 2001 1:13 PM
> To: Histonet
> Subject: Normal solution
>
>
> Help!  Can someone tell me exactly how to make a 2N and a 5N solution of
> sodium hydroxide?
>




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