action of less active metals on water?

Question

does magnesium powder react with h2o at ordinary temperature? and why?
at what instance that magnessium powder react with h2o?

Answer 1

The reaction of Mg powder with cold water (meaning at room T) is extremely slow and even negligible. Why ? the simplest answer is that Mg is not as reactive as other metals that react violently with cold water such as K, Na and Ca. (The reason for this can be explained in detail, which I will not go in to. )

Mg powder will react with hot water at a appreciable rate.

It will react violently with steam.

Answer 2

Magnesium reacts very slowly with cold water, and you can obtain a few cm3 of hydrogen per week:

Mg + 2H2O -----> Mg(OH)2+ H2

If steam is used, there is quite a violent reaction:

Mg + H2O -------> MgO + H2

Answer 3

Mg + 2 H2O ==> Mg^2+ + H2 (g) + OH^- so red litmus turns blue