Write the balanced equation for:

Magnesium nitride + water -> magnesium hydroxide + ammonia

MgNO2 + H2O -> MgOH + NH3

Is this correct?

magnesium nitride is Mg3N2.

Magnesium nitrite is MgNO2

so would it be

Mg3N2 + H2O -> 2MgOH + NH3

Almost. It forms Mg(OH)2 + NH3

The proposed balanced equation you provided is close, but there are a few errors. Let's correct them:

First, the formula for magnesium nitride is Mg3N2, not MgNO2. So the correct formula for magnesium nitride is Mg3N2.

Second, the formula for magnesium hydroxide is Mg(OH)2, not MgOH. So the correct formula for magnesium hydroxide is Mg(OH)2.

With these corrections, the balanced equation becomes:

Mg3N2 + 6H2O → 3Mg(OH)2 + 2NH3

To balance the equation, we need to ensure that the number of atoms of each element on both sides is the same. In this case, we have 3 magnesium atoms on both sides, 6 nitrogen atoms on both sides, 12 hydrogen atoms on both sides, and 2 oxygen atoms on both sides, ensuring that the equation is balanced.

If you encounter similar problems in the future, it's important to double-check the chemical formulas for each compound and ensure that the number of atoms of each element is balanced on both sides of the equation.