[rentj]

I did an experiment at school, where I put a sodium metal into distilled water (with PP indicator). There are fizzings, the solution turned color into pink, and the sodium metal started disappearing. I understand that the fizzing happened due to hydrogen gas being produced. Then, the solution turned pink because of the PP indicator in its base form (due to the alkaline condition, hydroxides being formed in the reaction). However, after I added the sodium, I also smelled an unpleasant odor, I believe it smells like those household LPG. I cannot find any reactions or literatures regarding the smell of that. Is that caused by impurities in the sodium metal? Or perhaps is it due to the solvent the sodium metal was initially stored in? Thank you.

[Borek]

Is that caused by impurities in the sodium metal? Or perhaps is it due to the solvent the sodium metal was initially stored in?

Both guesses are about as good as they can be. There is nothing that could produce any smell in the reaction between sodium and water itself (although heat produced can boil water so it is possible for the system to produce a mist consisting of small droplets of highly alkaline NaOH solution - it won't be smelly though, but choking).

[Corribus]

I do not know what LPG is (protip: do not assume people know what your acronyms stand for), but were I to throw out a guess, I would guess something to do with your indicator, which may partially decompose and aerosolize during the reaction, and/or solvent/oil that is still adsorbed on the sodium surface.