What happens to liquids when they get hot?

Take Water as an example. Upon heating it, it changes its state into vapor form. The reason behind this is the inter-molecular spaces and forces.

Liquids have less spaces as compared to gases .

Upon heating, the molecules gain Kinetic energy and start striking with each other at full force. This causes the molecules to move further away from each other.

As a result the inter-molecular forces weaken and the spaces increase.

Increase in inter molecular spaces means increase in volume of the substance and increase in volume means decrease in density as:

and this means that density and volume have an inverse relation.

As the volume increases and density decreases, liquids change their state and turn into gases.

Liquids expand and become less dense when their molecules gain energy and move more quickly. If the temperature rises to a certain point, the liquid may eventually reach its boiling point, at which point it evaporatively turns into a gas.

When liquids are heated, several changes occur:

1. Expansion: Liquids expand when heated because the molecules gain kinetic energy, causing them to move more rapidly and spread out. This expansion can lead to an increase in volume.

2. Decrease in Density: As liquids expand when heated, the density decreases. This is because the same amount of liquid now occupies a larger volume, resulting in fewer molecules per unit volume.

3. Change in Viscosity: Generally, the viscosity of liquids decreases as they are heated. Viscosity is a measure of a liquid's resistance to flow. With increased temperature, the movement of molecules becomes more chaotic, reducing the cohesive forces between them and making it easier for the liquid to flow.

4. Vaporization: Heating a liquid can lead to vaporization, where some of the liquid molecules gain enough energy to overcome the intermolecular forces holding them together and escape into the gas phase. This process can occur gradually (evaporation) or rapidly (boiling), depending on the temperature and pressure.

5. Changes in Solubility: The solubility of substances in a liquid may change with temperature. In some cases, heating a liquid can increase the solubility of certain substances, while in others, it may decrease solubility, leading to the formation of precipitates.

Overall, heating liquids causes them to undergo physical changes such as expansion, changes in density and viscosity, vaporization, and alterations in solubility. These changes are a result of the increased kinetic energy of the liquid molecules.