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Essay on Water
Introduction
Water is an essential ingredient for the existence of life as we know it.Biochemical processes occur in aqueous environments,many of which use water.Water also plays a significant role in the process of photosynthesis ( 6 CO2 + 6H2O + 672kcal -> C6H12O6 + 6O2 ).Photosynthesis is the most basic and significant chemical reaction on earth,providing the primary nutrients,directly or indirectly,for all living organisms and is the primary source of atmospheric oxygen.Without water and its unique and unusual properties,life as we know it on earth would not exist.Water is the only substance naturally present on the earth that exists in three distinct states -solid,liquid,and gas.Many of the unique properties in the take for granted include the three physical phases,transparency,universal solvents,density behavior and temperature,high specific heat,high heat of vaporization,viscosity,surface tension and low compressibility.To understand why these properties exist in water and why they are essential to life on earth it is important to look at the shape and bonding patterns of the molecule because the uniqueness of water is a direct result of its shape and bonding patterns.
Water鈥檚 Important Role
Water is the single most abundant molecule in living things.It provides the medium in which most biochemical interactions occur.Some biochemical reactions water is involved in are:cellular respiration,digestion,and photosynthesis.Water is the home for many animals,plants and micro-organisms.Water is involved in the cycling of all other material by living things both on a local and global scale.
Water has a number of unique and unusual properties that are responsible for its important roles it plays in the biosphere.
BOILING AND MELTING POINTS.Water has unusually high boiling and freezing points compared to other compounds with similar molecular structure.A comparison of boiling and freezing points can be seen in the following chart.Notice only water has a boiling and melting point that exists within the range of life.The boiling point of water is a unique 100oC results is and the freezing point is a remarkable 0oC due to the fact of the polar nature of the water molecule and hydrogen bonding.
Two important,but not unique,properties of water for life are that water is liquid at normal temperatures over much of the earth and that water is transparent.If water were not liquid,nutrients could not flow from soil to the roots of plants,blood could not circulate,and bodies of organisms would be so rigid that they could not move.If water were not transparent,light could not penetrate through cellular protoplasm into chloroplasts to drive photosynthesis in plants,you would be blind because light could not penetrate through the vitreous humor to the retina of your eyes,and light could not penetrate into lakes to allow growth of phytoplankton.Clearly life cannot exist without the amazing properties of water.
SOLVENT CAPABILITY.A solvent is a substance capable of dissolving another substance (solute) to form a homogeneous mixture (solution) at a molecular level.The polar nature of water makes it an excellent solvent especially with other polar compounds such as salts,alcohols,carboxylic compounds and many more.As a solvent water is unsurpassed in it鈥檚 ability to dissolve a wide range of inorganic and organic substances.More substances dissolve in water than any other known substance.The versitility of water as a solvent allows it to serve as the medium of transport for so many materials.This is true both for individual organism and for the biosphere as a whole.The essential transport systems including blood,lymph,and urine are all water based.Without water鈥檚 solvent capabilities to make three systems work,life could not exist.
A LESS DENSE SOLID FORM.Water exists in liquid form over a wide range of temperatures outside of which life processess are slowed down or halted completely.Between 4̊c and the freezing point at 0̊c,an amazing thing happens that occurs with very few substances,Water gradually expands becoming less dense.Water is the only substance where the liquid state is heavier than the solid state.All other substances the solid form is denser than the liquid form.Since the density of ice is less than that of liquid Walter,ice floats on water.It is very significant that ice expands and floats on water because if lakes and streams froze from the bottom to the top,aquatic life would not even exist,and climate and weather patterns would be altered drastically.This is an important quality of water because as ice forms it floats on top of the water.It acts to provide a thermal blanket for the rest of the water beneath and all its many life forms.This is important because if water behaved like all other substances,water bodies would freeze from the bottom up and in most cases would never thaw completely during summer.This would have a dramatic cooling effect globally and would impact all life on earth.
LARGE HEAT CAPACITY.The remarkable property of water is it鈥檚 extremely high capacity to absorb heat without a significant increase in temperature.We see examples of this all the time.For example,under the summer sun at the beach,sand will increase in temperature to the point where it is too hot to walk on,whereas the water temperature is still cool,even though both are heated by the same amount of solar heat energy.Water has the largest heat capacity of any common substance.This means that water takes more heat energy to raise the temperature of water a given number of degrees than for any other material.In cooling water gives up more heat than any other material.This property is important globally and individually.Individually,the high heat capacity buffers organisms from sudden extreme shifts in temperature which would be harmful to it.Globally,the oceans moderate seasonal temperature fluctuations.That is why coastal areas are cooler than inland areas at the same latitude.These differences influence the weather globally.And without weather changes life would be very unbearable.The absorption of huge amounts of solar heat energy by water during the day and the slow release of heat energy during the night is responsible for the moderate climate in the coastal areas.A wider range of temperatures typically exist inland away from bodies of water.If not for the vast oceans on earth tempering the climate life would not exist.This property combines with the MPIBP property to create the water cycle which supports life on earth.
HIGH HEAT OF VAPORIZATION.Water has an extraordinarily high heat of vaporization.On average it takes 580 calories to convert one gram of water into water vapour.A value that is higher than any other common substance.This property is of important significance to animals in regulating body temperature because of the large amount of body heat that is required to evaporate water (sweat).Without this property of water,organisms would overheat and die and the climate would be thrown into chaos.
Conclusion
All of these unusual properties stem from the unusual structure and bonding patterns of the water molecule.The molecule is strongly polar because of its uneven distribution of electrons.This allows water to interact easily with other polar substances which accounts for the great solvent power of water.The electronegativity difference between the oxygen and hydrogen atoms in water molecules is responsible for the establishing of hydrogen bonds between molecules.It is the mutual attraction of water molecules that accounts for the ability of water to remain liquid over a broad range of temperature (0oC-100oC) and also for its high heat of vaporization and high heat capacity.Water could not have all these special characteristics/properties without its unique shape and bonding patterns,life could not exist if not for these special properties of water,espacally the hydrogen bond.
You can order a custom essay,term paper,research paper,thesis or dissertation on water from our professional custom writing service which provides high-quality custom written papers on any topic.
Tags:chemistry essays,example essay,research paper on water,term paper on water,water essays,water papers
Introduction
Water is an essential ingredient for the existence of life as we know it.Biochemical processes occur in aqueous environments,many of which use water.Water also plays a significant role in the process of photosynthesis ( 6 CO2 + 6H2O + 672kcal -> C6H12O6 + 6O2 ).Photosynthesis is the most basic and significant chemical reaction on earth,providing the primary nutrients,directly or indirectly,for all living organisms and is the primary source of atmospheric oxygen.Without water and its unique and unusual properties,life as we know it on earth would not exist.Water is the only substance naturally present on the earth that exists in three distinct states -solid,liquid,and gas.Many of the unique properties in the take for granted include the three physical phases,transparency,universal solvents,density behavior and temperature,high specific heat,high heat of vaporization,viscosity,surface tension and low compressibility.To understand why these properties exist in water and why they are essential to life on earth it is important to look at the shape and bonding patterns of the molecule because the uniqueness of water is a direct result of its shape and bonding patterns.
Water鈥檚 Important Role
Water is the single most abundant molecule in living things.It provides the medium in which most biochemical interactions occur.Some biochemical reactions water is involved in are:cellular respiration,digestion,and photosynthesis.Water is the home for many animals,plants and micro-organisms.Water is involved in the cycling of all other material by living things both on a local and global scale.
Water has a number of unique and unusual properties that are responsible for its important roles it plays in the biosphere.
BOILING AND MELTING POINTS.Water has unusually high boiling and freezing points compared to other compounds with similar molecular structure.A comparison of boiling and freezing points can be seen in the following chart.Notice only water has a boiling and melting point that exists within the range of life.The boiling point of water is a unique 100oC results is and the freezing point is a remarkable 0oC due to the fact of the polar nature of the water molecule and hydrogen bonding.
Two important,but not unique,properties of water for life are that water is liquid at normal temperatures over much of the earth and that water is transparent.If water were not liquid,nutrients could not flow from soil to the roots of plants,blood could not circulate,and bodies of organisms would be so rigid that they could not move.If water were not transparent,light could not penetrate through cellular protoplasm into chloroplasts to drive photosynthesis in plants,you would be blind because light could not penetrate through the vitreous humor to the retina of your eyes,and light could not penetrate into lakes to allow growth of phytoplankton.Clearly life cannot exist without the amazing properties of water.
SOLVENT CAPABILITY.A solvent is a substance capable of dissolving another substance (solute) to form a homogeneous mixture (solution) at a molecular level.The polar nature of water makes it an excellent solvent especially with other polar compounds such as salts,alcohols,carboxylic compounds and many more.As a solvent water is unsurpassed in it鈥檚 ability to dissolve a wide range of inorganic and organic substances.More substances dissolve in water than any other known substance.The versitility of water as a solvent allows it to serve as the medium of transport for so many materials.This is true both for individual organism and for the biosphere as a whole.The essential transport systems including blood,lymph,and urine are all water based.Without water鈥檚 solvent capabilities to make three systems work,life could not exist.
A LESS DENSE SOLID FORM.Water exists in liquid form over a wide range of temperatures outside of which life processess are slowed down or halted completely.Between 4̊c and the freezing point at 0̊c,an amazing thing happens that occurs with very few substances,Water gradually expands becoming less dense.Water is the only substance where the liquid state is heavier than the solid state.All other substances the solid form is denser than the liquid form.Since the density of ice is less than that of liquid Walter,ice floats on water.It is very significant that ice expands and floats on water because if lakes and streams froze from the bottom to the top,aquatic life would not even exist,and climate and weather patterns would be altered drastically.This is an important quality of water because as ice forms it floats on top of the water.It acts to provide a thermal blanket for the rest of the water beneath and all its many life forms.This is important because if water behaved like all other substances,water bodies would freeze from the bottom up and in most cases would never thaw completely during summer.This would have a dramatic cooling effect globally and would impact all life on earth.
LARGE HEAT CAPACITY.The remarkable property of water is it鈥檚 extremely high capacity to absorb heat without a significant increase in temperature.We see examples of this all the time.For example,under the summer sun at the beach,sand will increase in temperature to the point where it is too hot to walk on,whereas the water temperature is still cool,even though both are heated by the same amount of solar heat energy.Water has the largest heat capacity of any common substance.This means that water takes more heat energy to raise the temperature of water a given number of degrees than for any other material.In cooling water gives up more heat than any other material.This property is important globally and individually.Individually,the high heat capacity buffers organisms from sudden extreme shifts in temperature which would be harmful to it.Globally,the oceans moderate seasonal temperature fluctuations.That is why coastal areas are cooler than inland areas at the same latitude.These differences influence the weather globally.And without weather changes life would be very unbearable.The absorption of huge amounts of solar heat energy by water during the day and the slow release of heat energy during the night is responsible for the moderate climate in the coastal areas.A wider range of temperatures typically exist inland away from bodies of water.If not for the vast oceans on earth tempering the climate life would not exist.This property combines with the MPIBP property to create the water cycle which supports life on earth.
HIGH HEAT OF VAPORIZATION.Water has an extraordinarily high heat of vaporization.On average it takes 580 calories to convert one gram of water into water vapour.A value that is higher than any other common substance.This property is of important significance to animals in regulating body temperature because of the large amount of body heat that is required to evaporate water (sweat).Without this property of water,organisms would overheat and die and the climate would be thrown into chaos.
Conclusion
All of these unusual properties stem from the unusual structure and bonding patterns of the water molecule.The molecule is strongly polar because of its uneven distribution of electrons.This allows water to interact easily with other polar substances which accounts for the great solvent power of water.The electronegativity difference between the oxygen and hydrogen atoms in water molecules is responsible for the establishing of hydrogen bonds between molecules.It is the mutual attraction of water molecules that accounts for the ability of water to remain liquid over a broad range of temperature (0oC-100oC) and also for its high heat of vaporization and high heat capacity.Water could not have all these special characteristics/properties without its unique shape and bonding patterns,life could not exist if not for these special properties of water,espacally the hydrogen bond.
You can order a custom essay,term paper,research paper,thesis or dissertation on water from our professional custom writing service which provides high-quality custom written papers on any topic.
Tags:chemistry essays,example essay,research paper on water,term paper on water,water essays,water papers
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