2021 · Q29
Manganese is extracted by heating manganese dioxide with aluminium powder. Which one of the following statements with regard to the reaction is correct?
general-sciencechemistry
- AThe reaction is exothermic.
- BThe reaction is endothermic.
- CManganese is produced as a solid.
- DManganese is more reactive than aluminium.
Explanation
The extraction of manganese by heating manganese dioxide with aluminium powder is a thermite-type displacement reaction. It is strongly exothermic — once ignited, it releases enough heat to sustain itself and melts the products. Aluminium is more reactive than manganese, which is why it displaces manganese from its oxide. Hence the statement that the reaction is exothermic is correct.