INTRODUCTION
The determination of whether a body of water is fit for consumption and all other factors concerning its physical and chemical state is known as water quality. Water (H2O) has a covalent bond as it consists of two non-metal substances (intramolecular bond). Intramolecular forces are the forces inside an individual molecule (chemical bonds) while intermolecular forces occur between molecules (physical interactions). Hydrogen can act as a metal or a non-metal and oxygens bond with hydrogen makes water special. Oxygen is a strongly electronegative substance while hydrogen is highly positive but when in the form of water the two hydrogen particles remain on one side leaving two pairs of unshared electrons, this results in oxygen have a slight negative charge and hydrogen a slight positive charge (refer to diagram 1). This creates a dipole-dipole force (intermolecular bond) which is responsible to water being adhesive and attracted to most substances. The slight polarity of water attracts other polar molecules, and that is why it is repelled by non-polar substances. The hydrogen bond occurring within water also accounts for the molecules strong cohesive …show more content…
Oxygen is insoluble with water and consequently it can only enter waterways via the natural flow of water (rapids, waterfalls) or by plants due to photosynthesis (Sydney Catchment Authority). Variations in dissolved oxygen levels can be both natural and unnatural. Dissolved oxygen levels can vary seasonally as they are greatly affected by the temperature as the higher it is the less soluble oxygen becomes. Also the greater the amount of bacteria and oxygen using bacteria, the less dissolved oxygen will be present. The average level of DO required by organism is >5mg/L and the average level of DO in freshwater at 27.5 degrees is 7.85mg/L
The determination of whether a body of water is fit for consumption and all other factors concerning its physical and chemical state is known as water quality. Water (H2O) has a covalent bond as it consists of two non-metal substances (intramolecular bond). Intramolecular forces are the forces inside an individual molecule (chemical bonds) while intermolecular forces occur between molecules (physical interactions). Hydrogen can act as a metal or a non-metal and oxygens bond with hydrogen makes water special. Oxygen is a strongly electronegative substance while hydrogen is highly positive but when in the form of water the two hydrogen particles remain on one side leaving two pairs of unshared electrons, this results in oxygen have a slight negative charge and hydrogen a slight positive charge (refer to diagram 1). This creates a dipole-dipole force (intermolecular bond) which is responsible to water being adhesive and attracted to most substances. The slight polarity of water attracts other polar molecules, and that is why it is repelled by non-polar substances. The hydrogen bond occurring within water also accounts for the molecules strong cohesive …show more content…
Oxygen is insoluble with water and consequently it can only enter waterways via the natural flow of water (rapids, waterfalls) or by plants due to photosynthesis (Sydney Catchment Authority). Variations in dissolved oxygen levels can be both natural and unnatural. Dissolved oxygen levels can vary seasonally as they are greatly affected by the temperature as the higher it is the less soluble oxygen becomes. Also the greater the amount of bacteria and oxygen using bacteria, the less dissolved oxygen will be present. The average level of DO required by organism is >5mg/L and the average level of DO in freshwater at 27.5 degrees is 7.85mg/L