Question

Identify the incorrect statement from the given definitions of solids, liquids and gases in terms of melting and boiling points.

• A. A substance is said to be in solid state if under normal pressure, its melting point is above the room temperature
• B. A substance is said to be in liquid state if under normal pressure, its melting point is below the room temperature
• C. A substance is said to be in gaseous state if under normal pressure, its melting point is below the room temperature
• D. A substance can exist in solid, liquid and gaseous state under normal pressure and room temperature

Answer 1

The correct option is D A substance can exist in solid, liquid and gaseous state under normal pressure and room temperature

A chemical substance is defined as any material with a definite chemical composition and characteristic properties. These are often called as pure. It can exist as solids,liquids or gases at normal temperature and pressure and may change between these phases of matter with changes in temperature or pressure. Hence, under normal temperature and pressure solid, liquid and gas can not exist.