Give the correct balanced equation for the single replacement reaction of magnesium with aluminum oxide. A) Mg + AlO → MgO + Al B) Mg + Al2O3 → MgO + Al C) 3Mg + Al2O3 → 3MgO + 2Al D) Mg + Al2O3 → MgO3 + Al2

C) 3Mg + Al2O3 → 3MgO + 2Al

Answer is "C".

Explanation

Single replacement reaction is a type of reaction which one reactant reacts with another and makes a product by replacing one element by another.

Mg (Magnesium) reacts with Al₂O₃ (Aluminium oxide) and produces MgO (Magnesium oxide) and Al (Aluminium) as products. Here Al is replaced by Mg. Reaction is

Mg + Al₂O₃ → MgO + Al

To balance the reaction equation, both left and right hand sides should have same number of atoms in each element.

Here,

Left Hand Side has Right Hand Side has

Mg = 1 atom Mg = 1 atom

Al = 2 atom Al = 1 atom

O = 3 atom O = 1 atom

First step : balance the O atoms in both sides. To do that "3" should be added before MgO.

Second step : After balancing O atoms, there will be 3 Mg atoms in right hand side. Hence to balance Mg atoms again "3" should be added before Mg in left hand side

Third step : as the final step balance the Al atoms by adding "2" before Al in the right hand side.

Then final balanced equation should be

3Mg + Al₂O₃ → 3MgO + 2Al