Q1. 2Mg + O2 → 2MgO. In the above chemical reaction, the magnesium metal is ________.
A Reduced
B Oxidised Correct
C Dissociated
D Displaced
Explanation
In this reaction, magnesium combines with oxygen to form magnesium oxide. Magnesium gains oxygen, and gain of oxygen is oxidation. In oxidation-number terms, magnesium changes from 0 in the metal to +2 in magnesium oxide, so it loses electrons and is oxidised. Reduced would apply to a species gaining electrons or losing oxygen, which magnesium does not do here. Dissociated means breaking into simpler species, not combining with oxygen. Displaced means replacing another element from a compound, which is also not happening. Therefore magnesium is oxidised.