Answer:
Mg₃N₂ + 4 H₂SO₄ ⇒ 3 MgSO₄ + (NH₄)₂SO₄
Step-by-step explanation:
To balance an equation, you need to make both sides of the equation have equal number of each element. Also, I think that you didn't write the whole equation since the reaction you gave is not likely.
Mg₃N₂ + 4 H₂SO₄ ⇒ 3 MgSO₄ + (NH₄)₂SO₄