Water
Because of its ubiquitous nature, water, stands out as a pertinent necessity for life. Virtually every single cell requires water for nourishment and for elimination of toxic substances. To perform such life dependent duties, water is endowed with exceptionally unique properties; properties that range from its heat and electrical conductivities, anomalous expansion to its density, viscosity and most importantly its impeccable dielectric strength in addition to its polarity that gives it the ability to dissolve a plethora of compounds that cannot be dissolved by other solvents.
One of the most significant unique properties of water is its polarity. Water is a polar solvent attributed to it is high electro-negativity that comes as a result of oxygen having the ability to pull more electrons to itself than hydrogen giving water a permanent dipole moment (Pauling, 1988). The dipole moment of water is responsible for its high dielectric constant of about 80 at room temperature (Pauling, 1988). All these jointly account for the ability of water to dissolve a variety of ionic substances (Pauling, 1988). Because of its ability to dissolve many substances, water enables plant and animal to transport mineral salts essential for their survival.
The specific heat- a measure of a material's thermal insensitivity- of water is another anecdotal property of water that makes it a vital component of plant and animal life. Water has an unusually high specific heat. Even though specific heat is known to vary with temperature, the specific heat of water only varies by about 1% within a temperature range of 0oC to 100oC. The high specific heat of water means a lot of heat is require to raise the temperature of water by one degree Celsius. In the same way, a lot of heat has to be removed from a water sample to reduce its temperature by one degree Celsius. Closely related to the high specific heat of water is its anomalous expansion. Water expands anomaly attaining a maximum density at a temperature of about 4oC on cooling after which the density begins to fall with further cooling (Pauling, 1988). This property is immensely useful in the preservation of aquatic life.
The surface tension and cohesive forces are, again, important properties of water with regards to plant and animal life. These two properties permit insects to walk on the surface of the water and hence are able to obtain food. Further, a strong adhesive characterizes water. The adhesive force is particularly salient in enabling plant absorb water from the soil which is then transmitted to other parts of the plant through a process called capillary action.
This precious commodity is all the times faced with the risk of contaminants that vary from microbial organisms to chemical elements that find their ways to the water sources through varied exposure pathways. Arsenic, mercury, zinc, nickel and lead are the most dangerous contaminants of water. These metals derive their toxicity from their valence states and existence forms. Aluminum, chlorides, sulphates are manganese are also possible contaminants of water. With reference to the importance of water initially asserted in this paper, it is logical to state that access to safe water should by all means be a basic human right: there is no way access to such an essential commodity can be a luxurious deed.
Soaps
Soaps are manufactured from the decomposition of fatty acids and alkali in the presence of glycerin (Pauling, 1988). Pauling (1988) describes soap as an emulsifying agent that has one part soluble in water and another part soluble in oil. In most cases, soaps are prepared from the reaction of Sodium Hydroxide or Potassium Hydroxide with animal fats. In the same light, the most common type of fatty acids used to make soaps are Oleic acids, stearic acid and palmitic acid (Pauling, 1988). The figure 1 shows a general structure of soap. The M can be either potassium or sodium. Sodium palmatate is a good example of soap with a chemical formula: C15H31COO-Na+. The C15H31 represents the tail whiles the COO-Na+ represents the carboxylic head.
Fig. 1
On dissolving in water, the oil-loving part of the soap attach to the dirt or oil particle on the skin or fabric forming a micelle; a round rind surrounding the dirt particle thereby breaking it into small globules through a process called emulsification. The water-soluble part projects towards the surface of the micelle carrying a negative charge. Two micelles are then formed with similar charges and hence cannot coalesce. Generally, the overarching idea behind the cleaning action of soap is emulsification of the dirt particle and the lowering of the surface tension of the water.
Chlorine and its Compounds
Chlorine is a poisonous gas, greenish yellow in color, generated in the laboratory from the reaction of hydrochloric acid and magnesium dioxide, electrochemical processes, which includes the electrolysis of hydrochloric acid. The chlorine element is highly reactive and hence it is obtained in forms of compounds and not in a free state. Sodium chloride is an example of a compound formed from the chlorine element with an assortment of chemical properties; it contains ionic bonds and it contains ions that make it soluble in water. Even though sodium chloride contains chloride atoms, the chloride atoms are not usually metabolized in the body. This explains why sodium chloride (table salt) is safe for human consumption. Sodium hypochlorite is another example of a chlorine compound prepared by bubbling chlorine through a solution of sodium hydroxide or by electrolysis of sodium chloride (Pauling, 1988). The hypochlorite ion is an exceptional oxidizing agent hence can be used as a bleaching agent (Pauling, 1988).
References
Pauling, L. (1988). General chemistry. Mineola, NY: Courier Dover Publications.
