Explain the following : (i) Gases exert pressure on the walls of the container . (ii) Water is liquid at room temperature. (iii) Evaporation causes cooling
Explain the following : (i) Gases exert pressure on the walls of the container . (ii) Water is liquid at room temperature. (iii) Evaporation causes cooling
(ii) Water is a liquid at room temperature due to the presence of hydrogen bonds between water molecules. The state of a molecule is determined by intermolecular forces, such as dipole-dipole interactions, Van der Waals forces (also called London dispersion forces), and hydrogen bonds.
This attractive force between molecules is very, very weak on one hand; but over large distances, however, these small attractive forces add into something very, very powerful. An overall sticky effect is created. "Sticky" in that the water molecules are more attracted to each other than molecules of that molecular mass would normally be. Molecules like oxygen gas and nitrogen gas are gases at room temperature. Because of the hydrogen bonding between water molecules, water is a liquid at room temperature. But however Water also evaporates from an open container at room temperature due to the kinetic energy that is at room temperature.
(ii) Water is a liquid at room temperature due to the presence of hydrogen bonds between water molecules. The state of a molecule is determined by intermolecular forces, such as dipole-dipole interactions, Van der Waals forces (also called London dispersion forces), and hydrogen bonds.
This attractive force between molecules is very, very weak on one hand; but over large distances, however, these small attractive forces add into something very, very powerful. An overall sticky effect is created. "Sticky" in that the water molecules are more attracted to each other than molecules of that molecular mass would normally be. Molecules like oxygen gas and nitrogen gas are gases at room temperature. Because of the hydrogen bonding between water molecules, water is a liquid at room temperature. But however Water also evaporates from an open container at room temperature due to the kinetic energy that is at room temperature.
