Water is a chemical compound comprised of two hydrogen atoms and one oxygen atom and is written in the chemical equation form of H2O. Water has a tetrahedral molecular shape which is also known as tetrahedral electron pair geometry (Ophardt, 2003). This arrangement is due to valence electron pairs, mutually repelling each other at a 109.5-degree angle. This repulsion is caused by a non-bonding pair of electrons and two hydrogen atoms which in turn repel against each other to form waters molecular shape. As a result of waters molecular shape, it has a bent molecular structure due to the oxygen atom having an un - shared pair of electrons.
Water has covalent bonds, which occur within a molecule and involves the sharing of valence electrons. The covalent bonds that hold both the hydrogen atoms and oxygen atoms together are very strong within the molecules, however, the forces holding water molecules to neighboring molecules is quite weak, these are known as intermolecular forces.
Intermolecular forces occur between water molecules and involves ion-dipole and …show more content…
A normal level of dissolved oxygen for freshwater body systems is > 5-6 Mg/L and should not go below 80- 90% saturation. Dissolved oxygen is measured in either milligram per litre (Mg/L), percent saturation or Parts Per Million (Ppm).
Biochemical oxygen demand is an important factor in determining water quality. It measures the amount of DO in a body of water, that is used by aerobic micro - organisms to dispose of organic materials. Bacteria use cellular respiration to decompose of organic substances according to the equation:
C6H12O6 + 6O2 → 6CO2 + 6 H2O + 36 or 38