Question

Generally, metallic oxides are basic and non metallic oxides are acidic in nature.

The solution of which of the following oxides in water will change the color of blue litmus to red?

• A. Sulfur dioxide
• B. Magnesium oxide
• C. Iron oxide
• D. Copper oxide

Answer 1

The correct option is A

Sulfur dioxide

The explanation for Correct Answer:

Option (A): Sulphur dioxide

1. $\mathrm{S}$ is a nonmetal and when it reacts with oxygen, it leads to the production of non-metallic oxides.
2. ${\mathrm{SO}}_2$ is a type of non-metallic oxide.
3. Usually, non-metallic oxides are acidic in nature because when they are reacted with water they form acidic solutions.$\underset{\mathrm{Sulfur}\mathrm{dioxide}}{{\mathrm{SO}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{water}}{2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}\to \underset{\mathrm{Sulfurous}\mathrm{acid}}{{\mathrm{H}}_2{\mathrm{SO}}_3\left(\mathrm{l}\right)}$
4. Therefore, only ${\mathrm{SO}}_2$ can covert blue litmus to red as it can only be done by acidic solution.

The explanation for Incorrect Answer:

Option (B): Magnesium oxide

1. Magnesium is metal and forms metallic oxides.
2. All the metallic oxides are either basic or amphoteric in nature.
3. Due to its basic and amphoteric nature, it cannot turn blue litmus to red.
4. Hence, it is an incorrect option

Option (C): Iron oxide

1. Iron is a transition metal and forms metallic oxides.
2. All the metallic oxides are either basic or amphoteric in nature.
3. Due to its basic and amphoteric nature, it cannot turn blue litmus to red.
4. Hence, it is an incorrect option

Option (D): Copper oxide

1. Copper is a transition metal and forms metallic oxides.
2. All the metallic oxides are either basic or amphoteric in nature.
3. Due to its basic and amphoteric nature, it cannot turn blue litmus to red.

Therefore, Sulfur dioxide in water will change the color of blue litmus to red.