Properties of water
Properties of water
- Water as a chemical it is a small molecule. Water has a low MW: 18, melting point :0°C, boiling point :100°C and it has apparent diameter of 2.5 Ao.
- Principle property of water is dipolar nature and hydrogen bonding.
- Structure which has both positive and negative charges on the same surface area are called as Polar/bipolar/dipolar structure.
- Water has high specific heat, heat of vaporization and heat of fusion.
- Amount of energy required to raise the temperature by one gram of water by 1oC is called specific heat. Energy required 4.184 J.
- Amount of energy required ired to change one gram of liquid water to water vapour is called as latent heat of vaporization. Energy required is 2452 J at 20oC.
- Amount of energy required to change one gram of liquid water to ice is called as latent heat of fusion. Energy required is 335 J.
- Water shows very high adhesive and cohesive property. Attraction between the unlike molecules [water and other charged molecules] or ability of a substance to have intermolecular attraction between dissimilar particles are called adhesive property.
- Ability of substance to have high enter molecular attraction between similar molecules is called cohesion property.
Due to adhesive and cohesive property of water, it develops other four properties.
-
Water develops high tensile strength: Ability of group of water molecules to withstand high levels of tension or negative pressure without getting separated itself. This property helps in bulk movement of water in plant system.
-
Water has high surface tension: Force acting invert within the molecules to keep the surface area as small as possible is called as surface tension.
-
Water develops high capillary force: Ability of liquid to raise to different levels in tubes of narrow diameter is called as capillary force.
-
Water has low viscosity: Ability of liquid to flow from one region to other region due to cohesion and adhesive property of water is called as viscosity.
-
Water has high dielectric constant: It is the ability of substance to neutralise the charges present on the surface of another substance is called as dielectric constant. Due this property water is called as universal solvent
|
Last modified: Thursday, 24 January 2013, 5:59 AM