Carbon monoxide is a/an:
A) Acidic oxide
B) Basic oxide
C) Amphoteric oxide
D) Neutral oxide

Hint: The molecular formula for carbon monoxide is CO. Carbon monoxide is a colourless, odourless and tasteless gas. The density of carbon monoxide is less than that of air. Carbon monoxide does not show acidic or basic properties on reaction with water.

Complete answer:
The binary compounds formed by the reaction of any metal or non-metal with oxygen are known as oxides.
Carbon monoxide is formed by the reaction of the non-metallic carbon with highly reactive oxygen. Thus, carbon monoxide is a non-metallic oxide.
The oxides that react with water to form acid or oxides that react with a base to form a salt are known as acidic oxides.
The oxides that react with water to form a base or oxides that react with an acid to form a salt are known as basic oxides.
The oxides which neither react with acids nor react with bases are known as neutral oxides.
The oxides which react with acids as well as react with bases to form a salt are known as amphoteric oxides.
Carbon monoxide neither reacts with acids nor reacts with bases.
Thus, carbon monoxide is a neutral oxide.

Thus, the correct option is (D) neutral oxide.

Note: A triple covalent bond is present in the carbon and oxygen atom of carbon monoxide. Carbon does not ionize and thus, it does not react with an acid or a base. Thus, carbon monoxide is a neutral oxide. Other examples of neutral oxides are: water, nitrous oxide, nitric oxide, manganese oxide.