Question

The pressure and temperature determine the state of a substance. Explain.

Answer 1

Hint: We know that there are three states of a substance: solid, liquid and gas. Solids have their own shape and volume. They have highly ordered structures. Liquids take the shape of the container but they have definite volume. Gases are free to move anywhere. They have low density and high compressibility.

Complete answer:
Matter can exist in a solid, liquid or gaseous state, and the state a substance is in can be largely determined by its temperature. According to Boyle’s Law, temperature and pressure are directly related, meaning that an increase in temperature results in a corresponding increase in pressure. This is again caused by the increase in kinetic energy associated with increasing temperature. At sufficiently low pressures and temperatures, solid matter may bypass the liquid phase and be converted directly from a solid to a gas through a process called sublimation.
Phase changes occur: When temperature or pressure change of a system occurs, phase changes occur. When the temperature or pressure increases, the interaction between the molecules increases. Similarly, when the temperature decreases, it is easier for molecules and atoms to settle into a more rigid structure. Effects of Pressure and temperature: Temperature is a measurement of the average kinetic energy of the molecules. Pressure is also a factor when examining the effects of temperature on the various states of matter.

Note:
Remember that in solids, the intermolecular forces are stronger since the particles are tightly packed with each other. In liquids, the intermolecular forces are not strong enough to keep the molecules from moving particles; hence liquids hold the shape of the container.