Answer is "C".
<em><u>Explanation
</u></em>
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,
<em>Left Hand Side has </em> <em>Right Hand Side has</em>
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
A) 2H₂(g) + O₂(g) → 2H₂O(l) + 285.83 kJ
Exothermic
B) 2Mg + O₂ → 2MgO + 1200kJ
Exothermic
Think it would be distillation
