I have one of those inexpensive kits for measuring TA. It came with a
bottle of 0.2N NaOH. I know that NaOH loses strength because it
combines with CO2 from the air. So the question is: how long can I keep
a partially full bottle of 0.2N NaOH until I have to throw it away and
get a new one? Weeks, months? I know that I can standardize it, but
that requires other chemicals and equipment, which I don't have. I
would just rather spend $6 every so often and be done with it. Thanks.