Ammonium formate is deliquescent and pretty soluble in water.
Thus leaving it out in the open air will cause it to quickly form a strong solution of the salt.
It is also the product of a weakish base and a strongish acid, hence solutions of it will tend to be acid except in the presence of excess base.
I would suggest adding strong ammonia solution to cooled formic acid and vacuum filtering off the precipitated salt after vacuum concentration if
required.
Transfer the product to a weighed jar and dry in a vacuum dessicator to constant weight. |