Question

magnesium oxide does not readily decompose into magnesium and oxygen. the reaction is shown below
mgo(s) + 601.7 kj → mg(s) + ½o₂(g)
which factor plays the most important role in allowing this reaction to occur?
○ temperature
○ concentration
○ pressure
○ surface area

Explanation:

The reaction \( \text{MgO}(s) + 601.7\ \text{kJ}
ightarrow \text{Mg}(s) + \frac{1}{2}\text{O}_2(g) \) is endothermic (requires heat, as energy is a reactant). Endothermic reactions often need a temperature increase to provide the necessary energy for the reaction to occur. Concentration affects reactions with dissolved species, pressure affects gas - phase reactions (here, only a small amount of gas is produced, and pressure changes won't drive this endothermic decomposition as much as temperature), and surface area affects reaction rate by exposing more reactant, but for this energy - requiring decomposition, temperature is key to provide the activation energy and the heat needed.

Answer:

A. temperature