Hi there, welcome to the community.
I'm not an expert but did a quick research with discordant results: some datasheets say water solubility (20°C) to be 450g/l, some others say 820g/l, others don't even mention it.
I don't know if solubility values are of concern, hopefully you'll get other answers.
Generally speaking, the most common mistakes people make when buying is getting nitrate (NaNO3) instead of nitrite (NaNO₂), or buying what is commonly referred to as "Prague powder", which is a mixture of salt with a little % of SN, which is useless.
Other values to correctly identify SN are:
# CAS: 7632-00-0
Molecular mass: 69,00 g/mol
pH: approx 9
Melting point: 271°C
Boiling point: 320°C
As far as purity goes, you need it to be minimum 95%, so yours should be good. Both food grade and lab grade are good as long as they match this value, although I would personally prefer to get some Lab grade (i.e. AGR = Analytical Grade) from a reputable chemical manufacturer. Moreover, you might want to test your product once you have it (plenty of infos using the search bar).
If you want you can post the full specifications you've come across but please, do not share website names, company names or logos as it's obviously forbidden on the forum.
Also, If you have an image with such specs you can post it but you must erase such info before posting.
