decomposition reactions

[ziggy777]

when studying the compound magnesium sulfide i read that the compound decomposes in water. ! does decompose means dissociates? like Mg2+ and S2- ?? I'm very confused....does MgS dissolves or not? I read on one website that it does. But other website says that it decomposes when placed in water and I also read that metals decompose when exposed to heat ... what exactly happens when MgS is placed in water?? is it soluble or not? Many Thanks!

[Sonic]

Decomposes means it chemically breaks down into smaller compounds/atoms whereas dissociating is when it splits into ions when placed in a solute.

I would not imagine it decomposes because MgS is pretty simple. I would imagine MgSO4 would undergo decomposition to give MgS but MgS itself I think is insoluble

[Sodapop]

when studying the compound magnesium sulfide i read that the compound decomposes in water. ! does decompose means dissociates? like Mg2+ and S2- ?? I'm very confused....does MgS dissolves or not? I read on one website that it does. But other website says that it decomposes when placed in water and I also read that metals decompose when exposed to heat ... what exactly happens when MgS is placed in water?? is it soluble or not? Many Thanks!The difference between decomposition and dissociation should look like this:

NH4+ ⇔ NH3 + H+

This is a dissociation. Like Sonic said, dissociating is when it splits into ions when placed in a solute. In this case, ions are formed, a dissociation has been made.

A decomposition is intimately similar, but a specific separation is made, and smaller compounds are formed, like in the following formula:

2H2O2 → 2H2O + O2

But as long as magnesium sulfide is concerned, I'm not so sure whether it's actually decomposable or not. :p

[ziggy777]

The difference between decomposition and dissociation should look like this:

NH4+ ⇔ NH3 + H+

This is a dissociation. Like Sonic said, dissociating is when it splits into ions when placed in a solute. In this case, ions are formed, a dissociation has been made.

A decomposition is intimately similar, but a specific separation is made, and smaller compounds are formed, like in the following formula:

2H2O2 → 2H2O + O2

But as long as magnesium sulfide is concerned, I'm not so sure whether it's actually decomposable or not. :p


it says that it decomposes when placed in water on WIKIPEDIA ???

you are quite right but not answering my question...does MgS dissociates or decomposes?