Answer
a) Surface Tension- Surface tension is the property of liquids due to which they tend to minimize their surface area.
b) Viscosity- Viscosity is a property of liquids by virtue of which they tend to resist their own flow.
c) Melting Point- Melting point is a temperature at which a solid gets converted to its liquid phase.
d) Boiling point- Boiling point can be defined as the temperature at which a liquid gets converted to its vapor form.
e) Vapor pressure- Vapor pressure is the pressure exerted by the vapors of a liquid over the liquid surface at equilibrium.
Work Step by Step
Surface Tension- The molecules of a liquid weakly attract each other. The molecules in the bulk of the liquid are surrounded by the same kind of molecules from all sides, and therefore experience the same kind of force from all sides, which cancel out each other. However, the molecules on the surface of the liquid are not surrounded by any molecule above them, therefore they experience a residual force from molecules in the bulk which attracts them. This leads to the liquid acquiring minimum surface area.
Viscosity- Just as friction is the resistance to move in solids, viscosity is the resistance offered by a liquid to flow. Different liquids have different viscosities. Higher the viscosity more is the opposition to flow. Viscosity generally decreases with an increase in temperature.
Melting Point- Melting point is the temperature at which a substance changes from its solid phase to the liquid phase. At this stage, the solid and liquid phases are considered to be in equilibrium with each other. Example- Melting point of water is $0^{\circ}C$. (Ice gets converted to water)
Boiling Point- Boiling point is the temperature at which a substance gets converted from its liquid phase to the vapor phase. At this stage, the liquid and vapor phase are said to be at equilibrium. Example- Boiling point of water is $100^{\circ}C$. (Water gets converted to steam.)
Vapor Pressure- It is the pressure which the vapors of a liquid exert over the surface of the liquid at thermodynamic equilibrium and at a certain temperature.
