Which of the following oxides is most basic?

\(MnO\)

The correct answer is (4) \(MnO\)

The basicity decreases with increasing oxidation state.

In \(MnO\), \(Mn\) has an oxidation state of \(+2\) and its least acidic and hence more basic.

Further, in case on \(Mn_2O_7\), \(Mn\) is \(+7\) oxidation state so it is more acidic and hence least basic

In general, the electropositive character of the oxide’s central atom will determine whether the oxide will be acidic or basic. The more electropositive the central atom, the more basic the oxide. The more electronegative the central atom, the more acidic the oxide.

The most basic oxides include:

1.Sodium oxide, which reacts with water to produce sodium hydroxide

2.Magnesium oxide, which reacts with hydrochloric acid to form magnesium chloride

3.Copper (II) oxide, which reacts with nitric acid to form copper nitrate.