WaTEr


WATER & Ph

Water is a chemical substance with the chemical formula H2O. Its molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. One molecule of water connected to each other by hydrogen bond. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice and gaseous state, water vapor or steam.

Properties of water

1.When water molecule are close to each other, they will arrange themselves in such a way that is positively charged hydrogen atom from one water molecule will be attracted to a negatively charged oxygen atom from another water molecule. Such electrostatic interactions that exist among polar molecules from hydrogen bonds. Hydrogen bond forms a strong force that holds the water molecules in place. This makes water a relatively stable compound.
2.Water has highest boiling point and therefore, remains liquid at room temperature. When heat energy is introduced, it will break the hydrogen bond between water molecules before it can increase their movement and turn to increase the temperature of water. Water has ability to resists temperature change.
3.Water is a universal solvent for polar(charged) molecules and thereby facilities chemical reactions both outside and within our body. Water dissolves polar compound easily due to the electrostatic interaction between water molecule and charged components in the compound.
4.Water has low viscosity.
5.Water exhibits high surface tension. Water molecule tends to stick together due to cohesive forces.
6.Water has a high specific heat capacity due to hydrogen bonding between its molecules. Thus, compared to other substances, water requires more heat to increase temperature. A large amount of heat causes a slight increase in temperature. The high specific heat capacity of water enables water temperature in cells to remain relatively constant.
7.Water moderates high temperatures through its high latent heat of vaporization, the amount of heat required to convert water from liquid to vapour.
8.Density of water decrease when below 4°C.

The importance of water

1.Water acts as an inert medium for many chemical reactions that take place in living organisms.
2.Water itself is involved in many chemical reactions.
3.Water acts as a medium of transport for dissolved nutrients within and between cells and also helps removal of waste.
4.Water acts a lubricants :
-Mucus helps earthworms and snails in movements. In mammals, mucus helps in the movement of food through the alimentary canal.
-Synovial fluid lubricates joints in vertebrates.
-Pleural fluid lubricates movements of lungs during breathing.
-Pericardial fluid lubricates movements of the hearts.
5.Water also acts as a carrier of heat and plays an important role during heat dissipation.
6.Water is also an important environmental factor that affects the life of organisms. A number of living organisms live in aquatic habitats.
7.Water has and continues to play a very important role in the evolution of biological systems on Earth.

pH of water

-Water is considered to be neutral. With a pH of 7.
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