I agree with you that if you're looking for commercially available formaldehyde, you'd mostly be sold the aqueous solution, i.e. the 1,1 dihydroxymethane , instead
this system has properties in its own right, yes .
...but those will differ from formaldehyde immensely
though of cause it is quite interesting to discuss those properties (esp. the gem. dihydroxy situation violating Erlenmeyer's rule) , my impression was that "newbiesig" wanted to know about formaldehyde, not about 1,1 dihydroxymethane instead
Another point i tend to disagree with you, in all respect , is that formaldehyde might be more or less nothing but a purely philosophical concept, whereas 1,1 dihydroxymethane would be the one and only real thing.
To the best of my knowledge, formaldehyde is a well known , stable substance , and even abundant in earth's atmosphere ( approx. 1 ppb , mostly from rotting organic materials ).
In technical processes it is widely used as pure gas - where available.
... because that's the problem with this material: you can't compress it very well without facing immediate polymerisation, and hence you'll have to look for a convenient transports form, which the waterbased system is.
Where'd you get the pKa value for those OH groups in the hydrate? I didn't bother to look them up because I thought it would be hard.
For example, Wikipedia (Ger ) has it (that's where I did look it up) , and Wikipedia (Eng), too, as I just found out , if you search for "Formaldehyde"