Chemical Connections. What sank the Titanic ? On april 12 1912, Titanic struck an Ice Berg in the...

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Transcript of Chemical Connections. What sank the Titanic ? On april 12 1912, Titanic struck an Ice Berg in the...

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Chemical Connections

What sank the Titanic ?On april 12 1912, Titanic struck an Ice Berg in the North Atlantic and within 3 hrs was resting on the bottom of the ocean.Of the 2300 passengers 1500 lost their lives.The Titanic was designed to be virtually unsinkable. Even a head on collision with another ocean liner, the ship was engineered to take from one to three days to sink.Thus the quick trip to the bottom has puzzled scientists for years.In 1991 a scientist named Steve Blasco from Canada proved that the steel with which the Titanic was built was not as ductile as it should have been. Further experiments in 1994 proved that the steel used to construct Titanic's hull was high in sulphur content and it is known that sulphur occlusions tend to make steel more brittle.

But in 1996 another team named RMS Titanic Inc headed by Tim Foocko showed that the rivets contain three times the expected amount of silica slag. Tim and his colleagues argued that the high slag resulted in weak rivets that snapped in large numbers when the collision occurred.

Lake Nyos Tragedy

On August 21 1986, a cloud of gas suddenly boiled from Lake Nyos in Cameroon, killing nearly 2000 people.At first it was speculated that the gas was hydrogen sulphide, but now seems clear that it was carbon dioxide.What would cause Lake Nyos to emit this huge suffocating cloud of CO2?Although the answer may never be known for certain,Many scietists believe this theory.Lake Nyos is a deep lake that is thermally stratified.Layers of warm less dense water near the surface float on the colder , denser water layers near the lakes bottom.Under normal conditions the lake stays this way, there is little mixing among the different layers.Scientists believe that over hundreds or thousands of years , carbon dioxide gas had seeped in to the cold water at the lakes bottom and dissolved in great amounts because of the large pressure of carbon dioxide present in accordance with Henrys Law.For some reason on August 21st 1986, the lake apparently suffered an overturn, possibly due to wind or due to unusual cooling of the lakes surface by monsoon clouds.This caused water that was supersaturated with CO2 to reach the surface and release tremendous quantities of gaseous carbondioxide that suffocated thousands of humans and animals before they know what hit them- a tragic monumental illustration of Henrys Law.Since 1986, the scientists studying Lake Nyos and nearby lake Monoun have obseved a rapid recharging of carbon dioxide levels in the deep waters of these lakes, causing concern that another deadly gas release could occur at any time. Apparently the only way to prevent such a disaster is to pump away the carbon dioxide. The project is yet to be funded by Cameroon.Beethoven Hair is the story

Beethoven , auguably the greatest composer who ever lived , had a troubled life , fraught with sickness, deafness, and personality aberrations.When Beethoven died in 1827, at the age of 56 many mourners took samples of the great mans hair. Infact it was said that at the time that he was practically bald by the time he was buried.The hair was recently analysed. According to William Walsh of the Health Research Institute in Chicago, Beethovens hair showed a lead concentration 100 times the normal levels. Beethovens exposure to lead came from the mineral water he drank and swam in when he visited spas.Lead poisoning may well explain Beethovens volatile temper.In rare cases lead poisoning has been known to cause deafness, but the researchers remain unsure if this problem led to Beethovens hearing loss. Chemistry doesn't leave you in the dark

All types of night vision equipments are electro optical devices that amplify existing light. A lens collects light and focuses it on an image intensifier. The image intensifier is based on the photoelectric effect- materials that give off electrons when light is shined on them.Night vision intesifiers use semiconductor based materials to produce large number of electrons for a given input of photons. The emitted electrons are them directed on to a screen covered with compounds that phosphorescence( glow when struck by electrons ).Night vision devises use phosphors that appear green, because human eye can distinguish more shades of green than any other color.Current night vision devices use gallium arsenide based intensifiers that can amplify input light as much as 50,000 times.Cadilac has recently included night vision as an option on its cars.How important are conversions from one unit to another?

NASA would say very very important.Because they lost 125 million US dollar Mars Climate Orbiter in 1999 due to a failure to convert from English to metric units. The problem arose because two teams working on the Mars mission were using different sets of units.Nasas scientists at the Jet propulsion Lab in Pasadena California assumed that the thrust data for the rockets on the orbiter they received from Lockheed Martin Astronautics in Denver , which built the spacecraft , were in metric units.In reality the units were English. As a result the Orbiter dipped 100 KM lower in to the Mars atmosphere than planned, and the friction from the atmosphere caused the craft to burn up.

In 1983 a Canadian jetliner almost ran out of fuel when someone pumped 22,300 pounds of fuel in to the aircraft instead of 22,300 kilograms.

So units are very important , they can mean the difference between life and death on some occassions.So remember to watch your units. Potassium- Too much of a good thing can kill you.

Our daily requirement of potassium is more than twice that for sodium.Because most food contain potassium, serious deficiency of potassium is rare.Potassium is found in the fluids of the body as K + ion and its presence is essential to the operation of our nervous system.The passage of impulse along the nerves require the flow of K + ion and Na + ion through the channels in the membranes of the nervous cells.Failure of this ion flow prevents nerve transmission and results in death.For example the black mamba snake kills its victims by injecting a venom that blocks the potassium channels in the nerve cells.Ironically too much potassium can be lethal. In fact the deadly ingredient in the drug mixture used for executing criminals is potassium chloride. Injection of a large amount of KCl produces an excess of K + ion in the fluids surrounding the cells and prevents the essential flow of K+ out of the cells to allow nerve impulse to occur.This causes heart to stop breathing.Death by lethal injection of KCl does not harm the organs of the body.Thus codemned criminals who are executed could potentially donate their organs for transplants. However this idea is very controversial.

Chemistry saves lives this way too.

Most experts agree that air bags represent a very important advance in automobile safety.These bags which are stored in the autos steering wheel are designed to inflate rapidly in the event of a crash cushioning the front seat occupants against impact. The bags are activated when a severe decceleration or impact compress a spring and electrically ignite a detonator cap, which in turn causes sodium azide ( NaN2) to decompose explosively forming sodium and nitrogen gas.2NaN2 (s) 2Na + 3N2 (g) .A relatively small amount of sodium azide 100g yeilds 56 L of N2 gas at 250C and 1 atm pressure. Sodium azide present in the activators must be given a proper disposal because besides being explosive, it has a toxicity roughly equal to that of sodium cyanide.Chemistry must have saved thousands of lives already and will continue to do so.

Self cleaning glass

Titanium dioxide is used a pigment in paper and paints.In recent years scientists have found a new use for TiO2 .When surfaces are coated with titanium dioxide , they become resistant to dirt and bacteria.Many glass companies now make glass that cleans itself, when they are coated with TiO2.All glass needs is sun and rain to keep itself clean.The self cleaning action arises from two effects. First the coating of TiO2 acts as a catalyst in the presence of UV light to break down carbon based pollutants to carbon dioxide and water.Second because titanium dioxide reduces surface tension of rain water sheets in stead of forming droplelts on the glass , thereby washing away the grime on the surface of glass.Because the TiO2 treated glass requires UV light for its action, it does not work well for interior surfaces where UV light is present in small amounts. However a team of Japanese researchers has found that if the TiO2 coating is doped with nitrogen atoms , it will catalyses the breakdown of dirt in the presence visible light as well.

Studies have shown that this N-doped TiO2 surface coating kills many types of bacteria in the presence of visible or ultraviolet light. This discovery could lead to products such as self sustaining bacteria tiles, and toilets. A Note-Able Achievement

Post it Notes a product of the 3M corporation, revolutionized casual written communication and personal reminders.Introduced in the United States in 1980s these sticky-but-not-too-sticky notes have now found countless uses in offices,cars, and homes throughout the world.The adhesive for Post it Notes was discovered by Dr.Spencer F Silver of 3M in 1968.Silver found that when an acrylic polymer material was made in a particular way, it formed cross linked mocropores. When suspended in a solvent and sprayed on a sheet of paper this substance formed a sparse monolayer of adhesive after the solvent evaporated.Scanning electron microscope images of the adhesive show that it has an irregular surface, a little like the surface of a gravel road. In contrast the adhesive on cellotape looks smooth and uniform, like a super highway. The bumpy surface of Silvers adhesive caused it to be sticky but not so sti