Question

what happens when magnesium oxide is dissolved in water ​

Answer 1

Answer:

Magnesium oxide is only very slightly soluble in water – so it won't be obvious that a small amount has dissolved – but if you now test the liquid with an indicator, it will give an alkaline reaction, showing that at least some Mg(OH)2, magnesium hydroxide, has been formed.

Answer 2

Answer:

When magnesium oxide is dissolved in water, basic compound Magnesium hydroxide is formed.

MgO + H2O --> Mg(OH)2

Hope this helps you.