When the ash obtained from burning magnesium is dissolved in water, the resulting solution is:

The correct option is

Basic, turning red litmus blue.

Explanation

Metals generally react with oxygen to form metallic oxides. These metallic oxides are basic in nature. When dissolved in water, they form metal hydroxides, which release hydroxide ions ($OH^-$), resulting in an alkaline solution.

Detailed Analysis

• Combustion of Magnesium: When magnesium ribbon is burnt in the presence of oxygen, it burns with a dazzling white flame and forms a white powder (ash). This ash is Magnesium Oxide ($MgO$).
  Reaction: $2Mg + O_2 \rightarrow 2MgO$
• Reaction with Water: When this magnesium oxide ash is dissolved in water, it reacts to form Magnesium Hydroxide [$Mg(OH)_2$].
  Reaction: $MgO + H_2O \rightarrow Mg(OH)_2$
• Nature of Solution: Magnesium Hydroxide is a base. According to the properties of indicators, bases turn red litmus paper blue. Acids, conversely, turn blue litmus red.

Key Takeaway: Oxides of metals are basic in nature and turn red litmus blue, whereas oxides of non-metals are acidic in nature and turn blue litmus red.