User:BEGEHWW
George Evans-Hulme
Profile
[edit]George E-H was born in 1996 in Wolverhampton, England. He now attends Kenilworth School. He created this page for a science homework ;-) And to prove this is MY work I am a year 10 student who takes History, Geography, Drama and french GCSE's. My sciene teachers are Mr White, Miss waite and Mrs McCarthy.
Electrolysis
[edit]Electrolysis is when an electric charge is method used for seperating elements bonded together, by passing an electric current through them.
It starts when the reactant is dissolved or melted so that the elements ions are 'available'. Two electric conductors are placed in the liquid, one (the Cathode) is negatively charged, the other (the Anode) is positively charged. These conducters both 'attract' the opposite charge. The Cathode would attract a positive and vice versa.
Hofmann Voltameter
[edit]A Hofmann voltameter is a basic piece of equipment which can be used for electrolysis. It consists of three glass tubes with middle one open topped (so you can add extra water or salts) The two electrodes at the bottem of the two outside glasses will be connected to the negative and positive terminals. When currents is run through the terminals the subtance (E.G water) will seperate into Oxygen and Hydrogen. the oxgen ion is negatively charged while the hydrogen ion is positively charged. The oxygen will appear at the Anode and the Hydrogen will appear at the Cathode.
The laws of Electrolysis
[edit]An English physicist named Michael Farday thought these up in 1832 and they have become universal.
The first Law
[edit]"The amount of any substance deposited, evolved, or dissolved at an electrode is directly proportional to the amount of electrical charge passing through the circuit."
This means that Larger electronic charges will alter more of the substance as an electrode.
The second Law
[edit]"The mass of different substances produced by the same quantity of electricity are directly proportional to the molar masses of the substances concerned, and inversely proportional to the number of electrons in the relevant half-reaction."
This basically means that y moles of electrons are needed to discharge an ion Xy+ or Xy-
Industrial uses
[edit]Electrolysis is used to seperate elements and compounds from each other. The most common industrial use is seperating metals from their ores.
- It helps produce Aluminium, Lithium, Potassium, Calcium and Magnesium.
- It helps produce Sodium Hydroxide and Chlorine.
- Production of Potassium Chlorate and Sodium Chlorate.
It has other uses such as
- Anodization which makes metal surfaces resistent to corrosion.
- The production of Hydrogen for fuel.
- It can be used to produce Oxygen for Spacecraft and Nuclear Submarines.
Bioleaching
[edit]Bioleaching is the use of Bacteria to extract Minerals from their ores. It is used by mining companies as it is a simpler than traditional extraction methods such as smelting or electrolysis. The bacteria ignore all the waste elements in Ore and gain energy by extracting these materials. The company than extracts the Ions from this solution. Bioleeching already accounts for 20% of the Worlds ined copper and is in use in about 20 mines around the world.
Why Bioleaching is good?
[edit]It is more enviorementally friendly than most extraction methods. For the company this can turn into aa profit as the necessary limiting of suphur dioxide is expensive.
Bioleaching is economic because it is simpiler to use and cheaper to build and mentain then other traditional methods.
The bad points
[edit]Bioleaching isn't without it's faults.
It's not totally economical though as the process is quite slower than other processes and it can delay income for new plants.
It isn't fully environmental either as the process cn produce harsh chemicals which can be leaked into the ground.
Phytomining
[edit]Phytomining or Biomining is the process when plants are used to mine heavy metals out of the ground, the plants are then burnt and the ashes contain the metal compounds absorbed by the plants.
This process can be used to extract heavy metals from contaminated land, plants such as Brassicas are used to take these materials out of the soil. Metals extracted can include Cadmium, Nickel and Cobalt.
Uses
[edit]This process is mostly used in America where there are several patents for Phytomining. The process is being considered for use in the UK and many other countries. This technique was also used in 1992 when it was used to stabilise heavy metals when the adit at the Wheal Jane Mine in Cornwall overflowed and released thousands of tons of cadmium, arsenic and lead into the Carnon River.
The future?
[edit]Phytomining is a real possibility for the future as it can stop enviromental destruction from harmful extraction processes. Plus it is a real possibility for extractiing a range of metals and it has the potential to exploit ore bodies, which would be uneconomical to mine by conventional methods.
Chemo and Radiotherapy
[edit]Chemotherapy
[edit]It was first used for cancer treatment in the 1920's although not for that specific purpose. A number of experiments in World War II caused the creation of the Cancer Chemotherapy National Service Center in 1955. In the 1960's and 70's they discovered how to treat more advanced forms of cancer. It destroys cancerous cells in the body by disrupting the division of cancerous cells in the body.
Radiothearpy
[edit]Wilhelm Röntgen discovered X-Rays in 1896 then a week later, they were used to treat cancer and then 3 years later they were used by Swedish scientists for radiotherapy. In the early days radiotherapy just consisted of one large dose of radiation. But now it consists of more accurate doses which targets the cancer cells. Radiothearpy is used for: As a stand-alone treatment to cure cancer; To shrink a cancer before surgery; To reduce the risk of a cancer coming back after surgery; To complement chemotherapy; To control symptoms and improve quality of life if a cancer is too advanced to cure.