Sciencemadness Discussion Board

Sodium sulfide and aluminium metal reaction

Foeskes - 3-9-2017 at 02:25

Yesterday, I bought some Na2S. Since I heard I was a strong base I wondered if it would act like NaOH on aluminium. So I made a concentrated solution and added aluminium foil. It reacted similar to aluminium and cold sodium hydroxide solution(although it heats up quick) and produces a really dark green solution. I'm assuming it's some kind of aluminium oxide sodium sulfide complex or something, since The reaction is similar to sodium hydroxide and aluminium producing NaAlO2(or NaAl(OH)4)

Melgar - 4-9-2017 at 04:06

It's probably black, as opposed to green. However, a black substance mixed with a yellow substance will often look dark green, and since elemental sulfur seems like one likely product of this reaction, that could explain the yellow.

I'm not sure why you're not considering aluminum sulfide species? Sodium doesn't really like being bonded to sulfide, or the rest of the elements in that group, for that matter.

Foeskes - 4-9-2017 at 14:32

Maybe so, I didn't consider Aluminium sulfide because it seems to be be unstable in water and hydrolyzes forming H2S.