Chemical Engineering
Factors affecting conductance.
Written by V R Saturday, 11 December 2010 16:41
The conductance of an electrolyte solution is influenced by the following factors.
- The nature of the electrolyte-whether it is strong or weak.
- Concentration of the solution.
- Temperature-as the temperature increases ionic mobility increases and hence the conductance.
- Ionic Size-The conductance decreases with increase in ionic size because of the increase of inter ionic interactions.
- Nature of interactions.
- Nature of the solvent.
Electrolytic conduction.
Written by V R Saturday, 11 December 2010 16:34
Electrolytic conduction involves the transfer of electrons by the movement of positive and negative ions towards the electrodes.Example in molten salts,acids and base electrolytic conduction takes place.Unlike electronic conduction chemical change occurs during electrolytic conduction.
In electrolytic conduction (i) ions move towards oppositely charged electrodes(ii) chemical changes takes place at the electrodes.(iii) Transfer of matter takes place in the form of ions.(iv) The resistance to the flow of current decrease with increase in temperature and hence increase in temperature increase the conduction.
Electronic Conduction.
Written by V R Saturday, 11 December 2010 16:09
Electronic conduction involves the direct transfer of electrons through the conductor under the influence of an applied potential.For example solid metals like copper and solid cadmium sulphide are electronic conductors.The resistance of an electric conductor to current passage can be determined by applying Ohm's law.According to this law
I=E/R
where I is the strength of current in amperes flowing through a resistance R in ohms under an applied potential difference E.This equation indicates that current strength is directly proportional to the difference in potential and inversely proportional to the resistance.
In electronic conduction (i)Electrons flow negative end to positive end.(ii) No change in the composition of the conductor(iii) No transfer of matter takes place.(iv) Resistance to the flow of current increases with increase in temperature and hence increase in temperature decrease the conduction.
Why do oil spill happens? Why did oil spill happen??? BP Oil Spill reasons
Monday, 03 May 2010 10:21
When we hear about an oil spill that has occurred in some part of the world we may be unaware of just how much oil has been spilled into either the water or on land. When we are talking about an oil spill, we are talking about a huge amount of oil that can do serious damage to the environment in which it was spilled.
How do Oil Spills happen?
Oil spills into rivers; bays and oceans are caused by accidents that usually involve tankers, barges, or refineries. Usually the oil is being transported to another part of the world for various reasons. People who by some form or another make mistakes or are being careless in what they are doing cause the spills themselves. Oil spills are not always caused by human mistake however; sometime machinery can break down which cause oil to spill out into the surrounding environment.
What happens when oil spills occur?
If an oil spill occurs in the ocean, the oil itself will float in salt water. It has been found that if the oil spill occurs in fresh water there is a good chance that the oil will float on top of the water as well. Believe it or not this is a good thing. This means that the oil is confined to the surface of the water, which makes containing the spill a little easier. The problem is that in water the oil will spread out quickly over the surface of the water. The more time the oil is left in the water the more it will spread out to cover a wider surface area, which can have a negative impact on the rate at which it can be contained and corrected.
When oil spills occur in the ocean there is always a chance that the marine life as well as birds and other animals will be negatively affected. Some oil spills have a greater impact on the wildlife then others, but no spill is good. Birds and other animals that are covered in fur, the oil itself actually destroys or breaks down the insulating ability of the fur. For birds, if the fur is covered in oil, the water-repelling abilities of the fur are affected. This exposed the animals to the harsh elements of the environments in which they live. There have been many animals killed as a result of oil spills in the oceans around the world.
Who takes care of Oils Spills?
When an oil spill occurs, who takes care of the problem? There are various, local and federal agencies that can be called upon to take care of oil spills. No matter who is called to take care of the spill the methods employed to clean up the spill are the same. Some agencies will be better equipped to clean up bigger spills whereas local agencies and organizations can handle the smaller, less dangerous spills. It is a criminal offence not to report an oil spill and failure to do so can result in jail time.
Was the BP Oil spill a real accident? Is it politics or something else?
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