[soda]

Hi,
Does anyone have any information on the stability or expiry date of 1M NaOH solution?
I was told 7 days, but I would have expected it to be longer as long as kept air tight to prevent interaction with CO2

Thanks

[enahs]

It depends on the conditions, container, lighting, etc etc.

But NaOH is a very poor standard, and if you need to use it very precisely you should first standardize your NaOH with a good standard. Usually KHP (potassium hydrogen phthalate)
http://en.wikipedia.org/wiki/Potassium_hydrogen_phthalate