6: Option - Shipwrecks, Corrosion and Conservation
6.1: The chemical composition of the ocean implies its potential role as an electrolyte
Identify the origins of the minerals in oceans as:
leaching by rainwater from terrestrial environments
hydrothermal vents in mid-ocean ridges
Identify - recognise and name
There are 2 major sources of the salts in seawater:
Leaching by rain and ground water.
Dissolution of salts by water passing through hydrothermal vents.
LEACHING BY RAIN AND GROUND WATER
The main ions that are dissolved as rainwater percolates through the soil and makes its way into creeks and rivers are Na, Ca, Mg, Cl and SO4.
Water that seeps down into underground aquifers dissolves greater quantities of these ions and under certain conditions (slightly lower pH than normal) picks up significant amounts of Hydrogen Carbonate (by dissolving carbonate)
Small amounts of nitrate and phosphate are also dissolved: these result from decay of plant and animal matter.
Although leaching of salts from the ground is a natural process, it has been significantly increased by human activities such as clear felling of forests, land clearing for pastoral pursuits and cultivation for crop growing.
Some underground aquifers pick up high concentrations of sodium chloride (from the many salt deposits that exist there), and these carry large amounts of salt to the oceans.
HYDROTHERMAL VENTS
Mid-ocean ridges (often containing fissures or cracks in the rock) exist near the Earth's crust.
Seawater is able to percolate down these fissures and come close to ...
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...Results:
Different metals and their corrosion rate
Metal Observation at start Observation of metal after 3 days
Aluminium Silver and shiny No change
Tin Silver and shiny No change
Zinc Silver and shiny No change
Iron Silver and shiny A coating of rust formed on the nail
Brass Gold and shiny A coating of corrosion formed on the topside of the tack and some corrosion was seen in the water.
Stainless Steel Silver and shiny No change
Plan and perform a first-hand investigation to compare the effectiveness of different protections used to coat a metal such as iron and prevent corrosion
Compare - show how things are similar or different
Gather and process information to identify applications of cathodic protection, and use available evidence to identify the reasons for their use and the chemistry involved
Identify - recognise and name
This experiment achieved the aim. It was concluded that acids and metal oxides form salt and hydrogen gas. Acids and carbonates form salts, water and carbon dioxide. Lastly, acids and bases result in salt and water.
As with cations, if the interaction between the anion and the hydrogen of the water is sufficiently strong, the hydrogen can be removed from the water generating a hydroxide ion resulting in a basic solution.
"Sodium chloride." Collins English Dictionary - Complete & Unabridged 10th Edition. HarperCollins Publishers. 27 Feb. 2012. .
The continents are old but the ocean floors are young do to volcanic activity from the ocean ridges. It is was difficult and complicated process for oceanographers and geologists to find about the shape of seabed. Seafloor features result from a combination of tectonic activity and the processes of erosion and deposition. Guyots are the flat-toped seamounts which were formed millions of years ago in the mid-ocean ridge crest due to volcanic eruptions. Magma from asthenosphere progressively shaped the seamount. Some seamounts were formed above the sea-level. Eventually, ocean floor moved and the seamounts were carried away as well, away from its source of lava and became non-active volcano or a seamount. This activity formed a chain of seamounts, tablemounts and islands. Some seamounts have its top above the sea-level. Seamounts with tops (islands) above the sea-level had their tops eroded by waves and wind, eventually, wearing the top down and thus formed a flat top. In millions of years, these flat-toped mounts (guyots) were submerged beneath the ocean and away from the mid-ocean
Living in a world that is roughly 70% water, and all living creatures found on this planet depend on this resource whether directly or indirectly, making water quality an important topic and vital to sustain our world of cycles. “Determination of status of water quality of a river or any other water sources is highly indeterminate. It is necessary to have a competent model to predict the status of water quality and to advice for type of water treatment for meeting different demands.” (Bai V, 2009) With most of our water on this planet made of salt water and our constant damage towards the remaining water that can be consumed by humans is diminishing with improper distribution on a global scale. If our greed comes before companionship, and our quality of life is more important than pollution, then our future generations to come will be born into a world of chaos, and a scarce of a basic human necessity.
Phosphorus is usually present in natural waters as phosphate(Mcwelsh and Raintree, 1998). Phosphates are present in fertilizers and laundry detergents and can enter the water from agricultural runoff, industrial waste, and sewage discharge (Outwater,1996) . Phosphates, like nitrates, are plant nutrients (Phosphates, 1997). When too much phosphate enters a water, plant growth flourishes (Phosphates). Phosphates also stimulate the growth of algae which can result in an algae bloom(World Book Encyclopedia,1999). . Algae blooms are easily recognized as layers of green slime, and can eventually cover the water's surface. As the plants and algae grow, they choke out other organisms. These large plant populations produce oxygen in the upper layers of the water but when the plants die and fall to the bottom, they are decomposed by bacteria which use a lot of the dissolved oxygen in the lower layers (Phosphates). Bodies of water with high levels of phosphates usually have high biological oxygen demand (BOD) levels due to the bacteria consuming the organic plant waste and subsequent low dissolved oxygen levels(Hooper,1998).
The Mid- Atlantic Oceanic Ridge is the best known divergent boundaries. Divergent boundaries are when two plates move apart from one another. The Mid-Atlantic Oceanic Ridge is spreading at an average of 2.5 centimeters a year ("Understanding plate motions [This Dynamic Earth, USGS]", 2014). This underwater mountain range a prime example of seafloor spreading as well. Seafloor spreading creates new oceanic lithosphere when the two plates pull apart and magma is allowed to well up and fill the crack. This also causes underwater mountains to form if the magma flows upwards past the crust (Tarbuck & Lutgens, 2015). It is important to understand how these ranges are created, especially because they can give scientists an idea on when new islands or continents may be formed. It also allows scientists to understand what may cause other plates to diverge from one
Finally, one major contributor of groundwater contamination is simply the chemicals we use every day. These chemicals include rock salt, pesticides,
When the water comes into contact with the pyrite, the chemical reactions that take place causes the water to increase in pH which will dissolve heavy metals which stay in solution. However, when the pH levels reach a certain stage, the iron can then precipitate out, coating sediments with the characteristic yellow, red or orange colourings (D.E.P. 2, 2002; U.S.G.S.; U.S.E.P.A., 2002). The rate that A.M.D. advances is also influenced by the presence of certain bacteria (Doyle; U.S.G.S). A.M.D that has dissolved heavy metals such as copper, lead and mercury can contaminate ground and surface water. Especially at risk are mines that are located above the water table (Keller, 2000; D.E.P. 2, 2002). The sources of water that get polluted can be surface water that permeates into the mine, shallow ground water flowing through the mine or any water that comes into contact with the waste tailings produced by mines.
PROPER IRRIGATIION CAN PREVENT SALT FROM BUILDING UP BECAUSE THE WATER CAN DRAIN THE SALTS AND SPREAD IT OUT SO THAT THE SALTS AREN’T CONCENTRATED IN ONE AREA!!!
This process takes place with carbon dioxide, it reacts with certain types of rocks forming a solution that can easily be carried by water. Then there’s lichens and acid rain. Lichens are a combination of fungi and algae and grow on rocks and produce acids that break down the minerals within the rocks. Leaching is the process of removing dissolved minerals as they are carried to lower layers in the soil. The chemical weathering processes need water and occur more rapidly at higher temperatures. So warm, damp climates are the best places where chemical weathering occurs. It would most likely occur most when it’s raining because chemical weathering needs water for the process/ processes to happen. Water also interacts with calcites in caves, causing them to dissolve. In addition to changing the shapes of rocks, chemical weathering from water changes the composition of water. Weathering over billions of years is a big
The most prevalent source of agricultural water pollution is soil that is washed off of fields. These fields have been treated with fertilizers and pesticides, which over time have accumulated heavy metals that are then transferred to lakes and streams. The excess particles cloud the water blocking vital oxygen and sun for the aquatic plants.
Corrosion is by far the greatest concern when it comes to aging aircraft. Corrosion is a deformity that occurs at the surface and subsurface of the structure and components of aircraft. This creates a greater need for advance techniques and inspections used to detect these deformities. Some techniques talked about in this paper that are used to detect corrosion are non-destructive testing, and different scheduled inspections.
Ocean water is often referred to as salt water. Ocean water becomes salty as water flows in rivers, it picks up small amount of mineral salts form rocks and soil of the riverbeds. This very-slightly salty water flows into the oceans. The water in the oceans only leaves by evaporating, but the salt remains dissolved in the ocean, it does not evaporate. So the remaining water gets saltier and saltier as time goes on.