Ga tau nih, bawaanya pengin pulang terusss...Males banget di kos, padahal malah aku bisa konsen belajar loh kalo d kos, tapi kenapa ya kok malah pengin pulang terus.Banyak banget tugas!!
Tagihan buat UTS juga, senin depan udah di-booking Environmental Chemistry, terus senin depannya lagi udah ujian Kimia Fisika lagi. Bayangpun...!!!
Belum lagi tugas akhir Review of High School Curriculum yang belum aku edit juga. Hmmm,,, kayaknya aku butuh sesuatu biar mendongkrak semangatku deh... apa yaa... OLAHRAGA!!!yups,,udah 2 minggu ini malah aku ga olahraga sama sekali..Pantes jadi males gini!!
OK..malam ini, deadline:
-Neliti laporan adik tingkat
-Ngerjain dasar teori laporan KF
-Nyicil Baca Inorganic Chemistry
-Nyatet Manajemen Laboratorium (nyalin dari orek2an)
-Baca2 tugas Review
-Nyoba ngerjain MSDS
-Huuuuwwwwhhhh....
Sayank,, aku kangen banget ni ma kamu, kapan ya bisa ketemu. Akar semua masalahku tu, karena gag ketemu kamu, jadi gag semangat gini deh!!!Kamu baek2 yaa di sana sayank!!
Nature has been transmuting dead life into black gold for millions of years using little more than heat, pressure and time, scientists tell us.
But with gas prices spiking more than $1 per gallon in the United States this year and some experts predicting that the end of oil is near, scientists still don't know for sure where oil comes from, how long it took to make, or how much there is.
A so-called fossil fuel, petroleum is believed by most scientists to be the transformed remains of long dead organisms. The majority of petroleum is thought to come from the fossils of plants and tiny marine organisms. Larger animals might contribute to the mix as well.
"Even some of the dinosaurs may have gotten involved in some of this," says William Thomas, a geologists at the University of Kentucky. "[Although] I think it would be quite rare and a very small and insignificant contribution."
But another theory holds that more oil was in Earth from the beginning than what's been produced by dead animals, but that we've yet to tap it. How it works
In the leading theory, dead organic material accumulates on the bottom of oceans, riverbeds or swamps, mixing with mud and sand. Over time, more sediment piles on top and the resulting heat and pressure transforms the organic layer into a dark and waxy substance known as kerogen.
Left alone, the kerogen molecules eventually crack, breaking up into shorter and lighter molecules composed almost solely of carbon and hydrogen atoms. Depending on how liquid or gaseous this mixture is, it will turn into either petroleum or natural gas.
So how long does this process take?
Scientists aren't really sure, but they figure it's probably on the order of hundreds of thousands of years.
"It's certainly not an instantaneous process," Thomas told LiveScience. "The rate at which petroleum is forming is not going to be the solution to our petroleum supplies."
The United States' latest reminder of its petroleum dependency occurred when hurricanes Katrina and Rita struck the Gulf of Mexico, where the majority of the country's oil platforms and refineries are located. Many analysts predicted gas prices would surge to $4 and $5 per gallon, but the fears turned out to be overblown. Many of the structures suffered only glancing blows and were operating again soon afterwards.
Still, the average price of regular gas nationwide is about $2.94 a gallon now, according to the American Automobile Association. It was $1.77 at the beginning of the year. Alternative source
The idea that petroleum is formed from dead organic matter is known as the "biogenic theory" of petroleum formation and was first proposed by a Russian scientist almost 250 years ago.
In the 1950's, however, a few Russian scientists began questioning this traditional view and proposed instead that petroleum could form naturally deep inside the Earth.
This so-called "abiogenic" petroleum might seep upward through cracks formed by asteroid impacts to form underground pools, according to one hypothesis. Some geologists have suggested probing ancient impact craters in the search for oil.
Abiogenic sources of oil have been found, but never in commercially profitable amounts. The controversy isn't over whether naturally forming oil reserves exist, said Larry Nation of the American Association of Petroleum Geologists. It's over how much they contribute to Earth's overall reserves and how much time and effort geologists should devote to seeking them out.
If abiogenic petroleum sources are indeed found to be abundant, it would mean Earth contains vast reserves of untapped petroleum and, since other rocky objects formed from the same raw material as Earth, that crude oil might exist on other planets or moons in the solar system, scientists say.
Both processes for making petroleum likely require thousands of years. Even if Earth does contain far more oil than currently thought, it's inevitable that reserves will one day run out. Scientists disagree sharply, however, on when that will occur. And, some say, a global crisis could begin as soon as increasing demand is greater than supply, a possibility that might be measured in years rather than decades, some analysts argue.
Nitrogen oxides play an important role in atmospheric processes. How are they formed, why are they important?
1. Traffic - still an important source of nitrogen oxides.(c) FreeFoto.com
Where do nitrogen oxides come from?
The most important nitrogen oxides are nitrogen monoxide NO and nitrogen dioxide NO2. Both together are called NOx. The nitrogen molecules (N2) in the air are very stable and it is not easy to oxidise them. A few bacteria have developed special mechanisms to crack the N-N triple bond and to form oxidised compounds. But by far more relevant are processes where the bonding is cracked by heat. This can only happen under extreme conditions. One example is during the combustion of fuel in a car engine. Most anthropogenic (= human made) NOx comes from this source. It can also happen during other very hot reactions, e.g. in the hottest parts of biomass burning flames. Finally lightning is a major source. In the flash channel temperatures reach up to 30,000 degrees Celsius and easily crack nitrogen bonds.
2. right: Lightning is another important source of nitrogen oxides.
picture by Bernhard Mühr Karlsruher Wolkenatlas
Where are they involved?
We find NOx (= NO + NO2) and other nitrogen oxides nearly everywhere in atmospheric chemistry. During the night, nitrate radicals NO3 are formed and are the most active oxidants. Radicals are chemical species, which are very instable and usually react extremely fast.
If N2O5 is formed in polluted areas, it can react on droplets or wet surfaces with water and nitric acid HNO3 is formed. HNO3 contributes to the acid character of the rain. Nitric acid, which can also be formed during the day by oxidation of NO2, is the main way how nitrogen oxides are removed again from the atmosphere, either by dry or by wet deposition (wash out by rain).
Nitric acid is also part of polar stratospheric clouds. Nitric acid tryhydrate forms the particles on which the ozone hole developed (details in 'Higher atmosphere - More - Unit 2').
Where do nitrogen oxides come from?
The most important nitrogen oxides are nitrogen monoxide NO and nitrogen dioxide NO2. Both together are called NOx. The nitrogen molecules (N2) in the air are very stable and it is not easy to oxidise them. A few bacteria have developed special mechanisms to crack the N-N triple bond and to form oxidised compounds. But by far more relevant are processes where the bonding is cracked by heat. This can only happen under extreme conditions. One example is during the combustion of fuel in a car engine. Most anthropogenic (= human made) NOx comes from this source. It can also happen during other very hot reactions, e.g. in the hottest parts of biomass burning flames. Finally lightning is a major source. In the flash channel temperatures reach up to 30,000 degrees Celsius and easily crack nitrogen bonds.
2. right: Lightning is another important source of nitrogen oxides.
picture by Bernhard Mühr Karlsruher Wolkenatlas
3. Where are nitrogen oxides involved in atmospheric processes? The scheme gives a little (not complete) overview of important processes in atmospheric chemistry.
Please click the scheme to enlarge! (100 K)
by Elmar Uherek for ESPERE
Where are they involved?
We find NOx (= NO + NO2) and other nitrogen oxides nearly everywhere in atmospheric chemistry. During the night, nitrate radicals NO3 are formed and are the most active oxidants. Radicals are chemical species, which are very instable and usually react extremely fast.
If N2O5 is formed in polluted areas, it can react on droplets or wet surfaces with water and nitric acid HNO3 is formed. HNO3 contributes to the acid character of the rain. Nitric acid, which can also be formed during the day by oxidation of NO2, is the main way how nitrogen oxides are removed again from the atmosphere, either by dry or by wet deposition (wash out by rain).
Nitric acid is also part of polar stratospheric clouds. Nitric acid tryhydrate forms the particles on which the ozone hole developed (details in 'Higher atmosphere - More - Unit 2').
Names of nitrogen compounds:
Formula
Systematic Name
Common Name
NO
nitrogen monoxide
nitric oxide
N2O
dinitrogen monoxide
nitrous oxide
NO2
nitrogen dioxide
nitrogen peroxide
N2O5
dinitrogen pentoxide
nitric anhydride
N2O3
dinitrogen trioxide
nitrous anhydride
HNO3
-
nitric acid
NH3
-
ammonia
Nitrogen oxides as gases are very important for the formation and degradation of tropospheric ozone, because they are involved in catalytic cycles. This is mainly, because NO2 can be photolysed by the sunlight. It forms NO and this NO is oxidised again to NO2. Ozone as well as organic peroxi-radicals (instable oxidised compounds) can be involved in this cycle as we see in detail in the next text.
The main reason for the invention of the catalytic converter for cars was, to avoid strong emissions of nitrogen oxides. We emit too much of them in combustion processes, especially in cars, and disturb the equilibrium in the air.
Nitrous oxide N2O is formed for example by baceteria in so called degradation processes. The microbiology of such tiny living organism plays a big role in the nitrogen cycle. But N2O does not react in the troposphere. It goes directly to the stratosphere, where it is split by sunlight (photolysed).
Ammonia NH3 is the most important basic gas in the atmosphere. Coming e.g. from livestock farming and fertilization, but also from microbiological degradation (bacteria), it can form salt particles of NH4NO3 together with nitric acid.
Nitrogen oxides at the crossways of atmospheric chemistry
Even if we do not have a closer look on nitrogen oxide chemistry, we can keep in mind, that these compounds are a little bit the heart of atmospheric chemistry. A major part of the chemical compounds, which are oxidised and removed from the atmosphere or transformed into other compounds come into touch directly or indirectly with NO or NO2.
4. Nitrogen oxides - in the centre of atmospheric chemistry
image: Elmar Uherek
Nitrogen gas, normally relatively inert (unreactive), comprises about 80% of the air. At high temperatures and under certain other conditions it can combine with oxygen in the air, forming several different gaseous compounds collectively called oxides of nitrogen (NOx). Nitric oxide (NO) and nitrogen dioxide (NO2 - the criteria pollutant) are the two most important.
Sources
Major sources of nitrogen oxides include
Fuel combustion in power plants and automobiles.
Processes used in chemical plants.
Health Effects
Certain members of this group of pollutants, especially nitrogen dioxide (NO2), are known to be highly toxic to various animals as well as to humans. High levels may be fatal, while lower levels affect the delicate structure of lung tissue. In experimental animals this leads to a lung disease that resembles emphysema in humans. As with ozone, long-term exposure to nitrogen oxides makes animals more susceptible to respiratory infections. Nitrogen dioxide exposure lowers the resistance of animals to such diseases as pneumonia and influenza. Humans exposed to high concentrations suffer lung irritation and potentially lung damage. Increased respiratory disease has been associated with lower level exposures.
The human health effects of exposure to nitrogen oxides, such as nitrogen dioxide, are similar to those of ozone. These effects may include:
Short-term exposure at concentrations greater than 3 parts per million (ppm) can measurably decrease lung function.
Concentrations less than 3 ppm can irritate lungs.
Concentrations as low as 0.1 ppm cause lung irritation and measurable decreases in lung function in asthmatics.
Long-term lower level exposures can destroy lung tissue, leading to emphysema.
Children may also be especially sensitive to the effects of nitrogen oxides.
Other Effects
Oxides of nitrogen also can:
Seriously injure vegetation at certain concentrations. Effects include:
Bleaching or killing plant tissue.
Causing leaves to fall.
Reducing growth rate.
Deteriorate fabrics and fade dyes.
Corrode metals (due to nitrate salts formed from nitrogen oxides).
Reduce visibility.
Oxides of nitrogen, in the presence of sunlight, can also react with hydrocarbons, forming photochemical oxidants, as discussed in the section on ozone. Also, NOx is a precursor to acidic precipitation, which may affect both terrestrial and aquatic ecosystems.
Oil spills often result in both immediate and long-term environmental damage. Some of the environmental damage caused by an oil spill can last for decades after the spill occurs.
Here are some of the most notable environmental damages typically caused by oil spills:
Oil Spills Damage Beaches, Marshlands and Fragile Marine Ecosystems
Oil spilled by damaged tankers, pipelines or offshore oil rigs coats everything it touches and becomes an unwelcome but long-term part of every ecosystem it enters.
When an oil slick from a large oil spill reaches the beach, the oil coats and clings to every rock and grain of sand. If the oil washes into coastal marshes, mangrove forests or other wetlands, fibrous plants and grasses absorb the oil, which can damage the plants and make the whole area unsuitable as wildlife habitat.
When some of the oil eventually stops floating on the surface of the water and begins to sink into the marine environment, it can have the same kind of damaging effects on fragile underwater ecosystems, killing or contaminating many fish and smaller organisms that are essential links in the global food chain.
Despite massive clean-up efforts following the Exxon Valdez oil spill in 1989, for example, a 2007 study conducted by the National Oceanic and Atmospheric Administration (NOAA) found that 26, 000 gallons of oil from the Exxon Valdez oil spill was still trapped in the sand along the Alaska shoreline.
Oil Spills Kill Birds
Oil-covered birds are practically a universal symbol of the environmental damage wreaked by oil spills. Any oil spill in the ocean is a death sentence for sea birds. Some species of shore birds may escape by relocating if they sense the danger in time, but sea birds that swim and dive for their food are sure to be covered in oil. Oil spills also damage nesting grounds, which can have serious long-term effects on entire species. The 2010 BP Deepwater Horizon offshore oil spill in the Gulf of Mexico, for example, occurred during prime mating and nesting season for many bird and marine species, and the long-term environmental consequences of that spill won't be known for many years. Oil spills can even disrupt migratory patterns by contaminating areas where migrating birds normally stop.
Even a small amount of oil can be deadly to a bird. By coating the feathers, oil not only makes it impossible for birds to fly but also destroys their natural waterproofing and insulation, leaving them vulnerable to hypothermia or overheating. As the birds frantically try to preen their feathers to restore their natural protections they often swallow some of the oil, which can severely damage their internal organs and lead to death. The Exxon Valdez oil spill killed somewhere between 250,000 and 500,000 seabirds, plus a number of shore birds and bald eagles.
Oil Spills Kill Marine Mammals
Oil spills frequently kill marine mammals such as whales, dolphins, seals and sea otters. The deadly damage can take several forms. The oil sometimes clogs the blow holes of whales and dolphins, making it impossible for the animals to breathe properly and disrupting their ability to communicate. Oil coats the fur of otters and seals, leaving them vulnerable to hypothermia.
Even when marine mammals escape the immediate effects, an oil spill can cause damage by contaminating their food supply. Marine mammals that eat fish or other food that has been exposed to an oil spill may be poisoned by the oil and die or can experience other problems.
The Exxon Valdez oil spill killed thousands of sea otters, hundreds of harbor seals, roughly two dozen killer whales and a dozen or more river otters. Even more troubling in some ways, in the years after the Exxon Valdez oil spill scientists noted higher death rates among sea otters and some other species affected by the oil spill, and stunted growth or other damage among other species.
Oil Spills Kill Fish
Oil spills often take a deadly toll on fish, shellfish and other marine life, particularly if large numbers of fish eggs or larvae are exposed to the oil. The shrimp and oyster fisheries along the Louisiana coast were among the first casualties of the 2010 BP Deepwater Horizon offshore oil spill. Similarly, the Exxon Valdez oil spill destroyed billions of salmon and herring eggs. Those fisheries still have not recovered. Oil Spills Destroy Wildlife Habitat and Breeding Grounds
The long-term damage to various species, and to the habitat and nesting or breeding grounds those species depend upon for their survival, is one of the most far-reaching environmental effects caused by oil spills. Even many species that spend most of their lives at sea—such as various species of sea turtles—must come ashore to nest. Sea turtles can be harmed by oil they encounter in the water or on the beach where they lay their eggs, the eggs can be damaged by the oil and fail to develop properly, and newly hatched young turtles may be oiled as they scurry toward the ocean across an oily beach.
Ultimately, the severity of environmental damages caused by a particular oil spill depends on many factors, including the amount of the oil spilled, the type and weight of the oil, the location of the spill, the species of wildlife in the area, the timing or breeding cycles and seasonal migrations, and even the weather at sea during and immediately after the oil spill. But one thing never varies: oil spills are always bad news for the environment.
Identifikasi Produk dan Perusahaan
Identifikasi Produk:
2% Pereaksi Asam Nitrat Blank
Nomor MSDS:
RB-HNO3-2
Identifikasi perusahaan:
High-Kemurnian Standar
PO Box 41727
Charleston, SC 29423
Telepon: (843) 767-7900
FAX: (843) 767-7906
Dalam hal panggilan darurat INFOTRAC: 800-535-5053
Identifikasi Bahaya
Darurat Ikhtisar: ber korosif. Dapat menyebabkan iritasi pada area kontak. Cuci daerah
kontak dengan air selama minimal 15 menit. Jika tertelan, jangan dimuntahkan. Mencairkan
dengan air dan hubungi dokter.
Target Organ: Mata, kulit, sistem pernapasan, gigi.
Kulit / mata Kontak: Cair dapat menyebabkan luka bakar pada kulit dan mata.
Inhalasi: May menyebabkan iritasi.
Tertelan: Dapat menyebabkan mual, muntah, dan diare. Tindakan Pertolongan Pertama
Inhalasi: Hapus untuk udara segar. Berikan pernafasan buatan jika perlu. Jika sulit bernapas, berikan
oksigen.
Kulit / mata Kontak: Hapus sepatu dan pakaian yang terkontaminasi. Siram daerah yang terkontaminasi dengan
banyak air selama minimal 15 menit. Panggil dokter jika iritasi berkembang.
Tertelan: Bilas mulut dengan air. Jika tertelan, jangan dimuntahkan. Jika sadar memberikan
besar jumlah air atau susu atau susu magnesium. CALL Seorang DOKTER dalam semua
kasus. Pemadam Kebakaran Tindakan
Api & Ledakan bahaya: Sementara asam nitrat tidak mudah terbakar, itu merupakan agen pengoksidasi kuat bahwa
dapat bereaksi dengan bahan mudah terbakar dan panas reaksi dengan mengurangi agen atau
bakar dapat menyebabkan pengapian. senyawa bisa dilepaskan dalam terjadi kebakaran. Bisa
bereaksi dengan logam untuk melepaskan gas hidrogen yang mudah terbakar.
Pemadaman Media: Gunakan media pemadam yang cocok untuk daerah sekitarnya. Gunakan
semprotan air untuk mencairkan asam nitrat dan untuk menyerap oksida nitrogen dibebaskan.
Metode Tertentu: Petugas pemadam kebakaran harus mengenakan perlengkapan pelindung yang tepat dan mandiri
alat bernafas dengan-wajah penuh sepotong dioperasikan dalam modus tekanan positif
Terkadang Release Tindakan
Ventilasi yang memadai diperlukan untuk menghilangkan nitrogen oksida dilepaskan dan, jika soda abu atau
batu kapur yang digunakan. Tinggal melawan angin dan jauh dari tumpahan. Pakailah pelindung diri sesuai
peralatan sebagaimana ditentukan dalam Bagian 8. Hapus sumber dari pengapian jika hidrogen bahaya. Tutup
tumpahan dengan natrium bikarbonat atau campuran kapur abu-soda (50:50) untuk menetralkan asam. Menjaga
sumber pengapian semua dan logam panas permukaan jauh dari tumpahan / rilis. Jauhkan bahan dari air
sumber dan selokan. Membangun tanggul menggunakan bahan inert (pasir kering yaitu atau di bumi) mengandung aliran
diperlukan. Tempatkan bahan dinetralkan ke dalam wadah yang cocok untuk pembuangan akhirnya, reklamasi,
atau perusakan. Selalu buang sesuai dengan peraturan setempat Penanganan dan Penyimpanan
Simpan di tempat yang sejuk, kering, berventilasi tempat penyimpanan dengan lantai tahan asam dan drainase yang baik. Jauhkan
sinar matahari langsung dan jauh dari panas, air, dan bahan-bahan yang tidak kompatibel. Ketika pengencer, asam
harus selalu ditambahkan perlahan ke air dan dalam jumlah kecil. Lihat Bagian 8 untuk pribadi
penanganan instruksi
Exposure Kontrol dan Perlindungan Pribadi
Rekayasa Kontrol: Sediakan ventilasi atau kontrol teknik lain untuk menyimpan
penumpukan kontaminan udara di bawah ambang batas nilai masing-masing. Pastikan
ketersediaan stasiun obat cuci mata dan pancuran keselamatan.
Perlindungan Pribadi: Pakailah sarung tangan yang tepat, kacamata keselamatan dengan perisai sisi, jas lab / celemek
Informasi toksikologi
Mei sangat mempengaruhi kulit, selaput lendir dan mata. Menelan dapat menyebabkan negatif
efek pada mulut dan tenggorokan dan resiko perforasi atau korosi kerongkongan dan
perut.
Toksisitas Data:
HNO
3
-RTECS # QU5775000
LD
LO
Oral, Manusia: (Nitric Acid) 430 mg / kg
Informasi Ekologi
Ekotoksikologi informasi: Jangan biarkan bahan untuk mencapai air tanah, badan air, atau
limbah sistem
Pertimbangan Pembuangan
Umum: Ikuti federal, dan peraturan daerah negara untuk limbah asam.
Peraturan (Tidak dimaksudkan untuk menjadi semua-dipilih regulasi inklusif terdaftar)
TSCA Status: Komponen larutan ini dicatatkan pada Inventarisasi TSCA.
RCRA Status: Tidak
SARA: Tunduk pada persyaratan pelaporan Pasal 313 dari SARA Judul III dan dari 40 CFR
372
Risiko Phrases: R20/21/22, Berbahaya bila terhirup, kontak kulit, atau jika tertelan.
Keselamatan Phrases: S36/37/39 Pakailah pakaian pelindung yang sesuai, sarung tangan dan mata / pelindung wajah
WHMIS Informasi (Kanada): E: Korosi
We humans love to get close to these clever, cute and cuddly sea-creatures, but do you know how they treat their women in the world of dolphin debauchery? Do you really want to?
Ever since Flipper appeared on our screens we’ve known dolphins to be highly intelligent, social creatures with an advanced communication system and the tendency to help humans when in trouble. Many of us have seen them performing tricks in captivity or watched them on television displaying the same manoeuvres in the wild. Some of us (including myself) have even been lucky enough to swim with one. But how many of us are aware of their slightly less courteous behaviour?
Dolphins have a dark side, too…
Researchers have been studying the sexual behaviour of dolphins intensely for the last decade, after it was discovered they not only partake in homosexual activity (read more HERE), but also gang-rape and kidnap females who don’t reciprocate their sexual advances.
In order to coerce the reluctant females, males form groups of two or three – often remaining together in their search for sexual gratification for well over a decade. When they find a suitable female they literally force her to mate with one or more of the group, and have even been known to herd their unwilling consorts for months at a time, basically using them as their personal sex-slaves.
Although dolphins are not alone in the animal world of gang-rapists, research suggests they’ve the perfected the art to a degree unseen in any other species, and it seems they don’t limit their advances to their female partners, either: there are several reports claiming divers and swimmers have also been accosted.
Google unveiled a powerful new mapping tool at the Cancun climate talks on Thursday that allows scientists to monitor changes in the Earth’s environment as climate change accelerates.
The search giant’s philanthropic arm, Google.org, calls the new Google Earth Engine “a planetary-scale platform for environmental data and analysis.” It combines Google Earth’s maps with 25 years’ worth of Landsat satellite images and other data.
Just as important as that data goldmine is Google’s move to put its immense computing resources at scientists’ disposal. Google.org is donating 20 million computational hours over the next two years to developing countries so they can monitor their forests as the United Nation’s prepares to implement an initiative called REDD, Reducing Emissions from Deforestation and Forest Degradation in Developing Countries.
“Deforestation releases a significant amount of carbon into the atmosphere, accounting for 12-18 percent of annual greenhouse gas emissions,” Rebecca Moore, the engineering manager for Google Earth Engine, wrote in a blog post. “For the least developed nations, Google Earth Engine will provide critical access to terabytes of data, a growing set of analytical tools and our high-performance processing capabilities. We believe Google Earth Engine will bring transparency and more certainty to global efforts to stop deforestation.”
For instance, scientists processed 8,000 Landsat satellite images on Google Earth Engine to create a map of the Democratic Republic of the Congo that shows the loss of forest cover over the past decade.
Scientists also used more than 53,000 satellite images taken between 1984 and 2010 to develop an extremely detailed forest cover and water map of Mexico. The Google Earth Engine tapped 1,000 servers to perform the 15,000 hours of computation needed to create the map in less than a day.
“As we fully develop the platform, we hope more scientists will use new Earth Engine API to integrate their applications online — for deforestation, disease mitigation, disaster response, water resource mapping and other beneficial uses,” Moore wrote. “We look forward to seeing what’s possible when scientists, governments, NGO’s, universities, and others gain access to data and computing resources to collaborate online to help protect the earth’s environment.”
Vegetable oil is a widely unrealized alternative fuel source, but only diesel engines can run on vegetable oil. Diesel engines are popular for being an efficient way to utilize alternative fuels as they run on petroleum diesel, biodiesel and straight vegetable oil. In addition to a number of commercially manufactured motorcycles that are now being produced with diesel engines, through a few simple modifications a motorcycle can be converted to run on vegetable oil.
Step 1
Purchase a motorcycle with a diesel engine, or replace a gasoline engine with a diesel. Only diesel engines without rubber seals can be converted to run on vegetable oil. These tend to be in newer model engines, but the seals can be removed from older models to run on vegetable oil. There are a few motorcycles on the market with diesel engines, specifically the Neander and the Kawasaki KLR650. If you chose to customize a bike with a diesel engine, adjust the transmission ratios to be compatible with the new engine’s RPM.
Step 2
Install a vegetable oil fuel conversion kit. You should keep the original gas tank to hold regular diesel or biodiesel fuel for cold weather. Install a second tank for vegetable oil. The conversion kit includes two or more hoses leading from the bike’s radiator to the vegetable oil tank that heat the oil through a heat exchanger before it enters the final fuel filter and injectors inside the engine.
Step 3
Install an auxiliary fuel system that can be activated by switch once the proper operating temperature has been achieved. This will shift your engine from running on diesel to running on vegetable oil. When operating the bike in cold weather, it is also advisable to switch back to diesel use 10 minutes before cutting the engine off. This will purge the engine to keep the vegetable oil from thickening and clogging when parked in cold climates.
Advanced battery technologies are enabling a much cleaner alternative to pollution-spewing gas-powered motorcycles and could help promote a larger-scale move toward electric vehicles. Yesterday, an electric scooter with motorcycle-like performance made by Vectrix, based in Newport, RI, was delivered to its first customer. And next year at least two motorcycles powered by advanced lithium-ion batteries will be sold in the United States.
Although conventional motorcycles get extraordinary gas mileage--with many getting more than 50 miles per gallon--they emit more pollution than even large SUVs because they aren't equipped with equivalent emissions-control technology. Indeed, with new emissions standards, SUVs are 95 percent cleaner than motorcycles, according to the Environmental Protection Agency. So while motorcycles could help reduce oil consumption and greenhouse-gas emissions, these gains come at the price of dirtier air. Electric motorcycles eliminate tailpipe emissions, keeping pollution out of the city, and they can be powered with clean sources of electricity. What's more, electricity costs less than gasoline. Vectrix estimates that it will cost riders just a couple of cents a day to operate its scooter.
All three battery-powered vehicles are limited in speed. The fastest is the Vectrix scooter, which can go 65 miles per hour. The speeds could be increased if the manufacturers were to change the gear ratio, which is currently designed for urban settings and motocross, for which acceleration is more important than sustained high speed.
Electric motorcycles are practical today because of advances in battery technology. Lead-acid batteries, which have been used in electric motorcycles in the past, are very heavy, provide a short range, and last for only a couple of years. The Vectrix scooter ($11,000) uses nickel metal hydride batteries--the same type used now in the popular Toyota Prius hybrid. This type of battery is lighter than lead-acid batteries and more durable: Vectrix claims it has a 10-year lifetime. Lithium-ion batteries, in turn, are lighter than nickel metal hydride, and new chemistries have made them durable as well, lasting as long as or longer than nickel metal hydride batteries. The Vectrix scooter weighs about 200 kilograms, while the lithium-ion-powered Enertia ($12,000), made by Brammo Motorsports of Ashland, OR, weighs just 125 kilograms. Brammo hopes that the lighter electric motorcycles will be appealing to those who would be intimidated by a heavier bike.
The batteries' light weight also makes them appealing for motocross bikers. Zero Motorcycles, based in Scotts Valley, CA, sells an off-road motorcycle ($7,000) that easily makes 20-meter jumps and will be featured in the extreme-sports showcase X Games, says Neil Saiki, who invented the motorcycle. It weighs just 54 kilograms, which is made possible in part by leaving the battery charger off the motorcycle. The company plans to sell a street version next year that includes the charger. The batteries Zero Motorcycles uses are known for their high power. They come from A123 Systems, of Watertown, MA, the company that makes the batteries used in a record-holding electric drag-racing motorcycle that can finish a quarter mile in just 8.17 seconds, reaching 156 miles per hour. The Enertia uses battery cells and packs from Valence Technologies, based in Austin, TX, whose cells have been used in the Segway personal transport.
Natrium telah lama dikenal sebagai senyawa, namun berhasil ditemukan pada tahun 1807 oleh Sir Humphrey Davy dalam elektrolisis soda kaustik. Pada zaman pertengahan Eropa senyawa natrium dengan nama Latin sodanum digunakan sebagai obat untuk sakit kepala. Simbol natrium (Na) berasal dari nama neo-Latin,
sedangkan untuk sejenis senyawa natrium biasa bernama natrium yang berasal dari Bahasa Yunaninítron sejenisgaram. Pada awal 1860 Kirchhoff dan Bunsen telah mencoba kepekaan uji nyala yang terdapat pada natrium. Dijelaskan dalam Annalen der Physik und der Chemie dalam kertas kerja "Chemical Analysis by Observation of Spectra".
Pada penghujung abad ke-19, natrium disediakan secara kimia dengan memanaskan natrium karbonat dengan karbon ke suhu 1100 °C.
Na2CO3 (aq) + 2 C (s) → 2 Na (aq) + 3 CO (g).
Nartium pada masa kini dihasilkan secara komersil melalui elektrolisislarutan natrium klorida. Ini dilakukan dalam sebuah sel Down di mana NaCl dicampurkan dengan kalsium klorida untuk menurunkan titik leburke bawah 700 °C. Oleh sebab kalsium lebih elektropositif daripada natrium, tidakada kalsium yang dihasilkan pada katoda. Cara ini adalah lebih murah daripada cara sebelumnya yaitu mengelektrolisis natrium hidroksida. Logam natrium berharga kurang lebih 15 hingga 20 sen Amerika per paund (US$0.30/kg hingga ke US$0.45/kg) pada tahun 1997 sementara gred reagen (ACS) natrium berharga kurang lebih US$35 per paund (US$75/kg) pada tahun 1990.
Definisi Natrium
Natrium atau sodium adalah unsur kimia dalam tabel periodik yang memiliki simbol Na dan nomor atom 11. Selain itu natrium juga terletak pada golongan IA periode 3. Natrium adalah logam reaktif yang lunak, ringan, keperakan, dan seperti lilin, yang termasuk ke dalam logam alkali yang banyak terdapat dalam senyawa alam. Dia sangat reaktif, apinya berwarna kuning, bereaksi secara hebat dengan air dan teroksidasi dalam udara, maka ia memerlukan penyimpanan dalam lingkungan yang lengai seperti dalam minyak tanah (kerosin).Uji nyala natrium menghasilkan pancaran kuning yang terang disebabkan karena pada saat dipanaskan elektron dalam natrium mengalami eksitasi. Kemudian saat elektron akan kembali ketempat semula elektron melepaskan energi berupa energi cahaya dengan panjang gelombang tertentu.
Karena sangat reaktif, natrium hampir tidak pernah ditemukan dalam bentuk murni. Namun, biasanya ia tidak meledak di udara bersuhu di bawah 388 K. Natrium juga merupakan elemen terbanyak keempat di bumi, terkandung sebanyak 2.6% di kerak bumi. Unsur ini merupakan unsur terbanyak dalam grup logam alkali.
Sifat – sifat kimia dan sifat – sifat fisika logam natrium terdapat pada tabel berikut ini :
Terdapat tiga belas jenis isotop natrium yang telah ditemukan. Isotop yang stabil hanyalah 23Na. Natrium mempunyai dua isotop kosmogenikradioaktif (22Na, waktu paruhnya = 2.605 tahun; dan 24Na, waktu paruhnya ≈ 15 jam). Isotop – isotop tersebut terdapat dalam tabel berikut :
Sebuah lempeng kecil dari natrium yang dimasukkan ke dalam etanol akan bereaksi stabil menghasilkan gelembung-gelembung gas hidrogen dan membentuk larutan natrium etoksida yang tidak berwarna, CH3CH2ONa. Natrium etoksida juga dikenal sebagai alkoksida. Jika larutan diuapkan sampai kering, maka natrium etoksida akan tertinggal sebagai sebuah padatan putih.
Walaupun jika dilihat sekilas tampak sebagai sebuah reaksi yang baru dan cukup rumit, namun sebenarnya reaksi ini sama persis dengan reaksi antara natrium dan air (kecuali reaksinya yang berlangsung lebih cepat).
Mari kita bandingkan antara kedua reaksi ini:
Untuk reaksi antara natrium dengan air, tentu saja kita biasa menuliskan hasil reaksinya, natrium hidroksida, sebagai NaOH dan bukan HONa – inilah sebenarnya yang membedakan, yakni hanya dari segi penulisan sebagaimana ditunjukkan pada gambar di atas. Natrium etoksida sangat mirip dengan natrium hidroksida, kecuali bahwa hidrogen digantikan oleh sebuah gugus etil. Natrium hidroksida mengandung ion-ion H- sedangkan natrium etoksida mengandung ion-ion CH3CH2O-.
b.Reaksi eksplosif Natrium dengan Air
Saat natrium dikontakkan dengan air (H2O), reaksi kimia yang sangat eksotermik terjadi antara kedua reaktan tersebut dan membentuk natrium hidroksida (NaOH) dan hidrogen (H2).
Na(s) + H2O(l) –> NaOH(aq) + H2(g) + panas
Reaksi tersebut merupakan reaksi yang amat eksoterm dan cukup untuk membuat hidrogen terbakar karena keberadan oksigen di atmosfer. Reaksi hidrogen dan oksigen kemudian membentuk molekul air yang baru. Reaksi tersebut bersifat sangat eksotermal (menghasilkan panas), sehingga gas hidrogen secara otomatis akan terbakar, ini disebabkan karena gas hidrogen mengalami proses autoignition akibat perpindahan panas dari reaksi ke lingkungan.
2H2(g) + O2(g) –> 2H2O(g)
c.Reaksi Natrium dengan Chlorine (pembentukan garam)
Gambar di atas adalah proses pembentukan senyawa ion NaCl.
Pada awal mula kita belajar kimia, yang kita ketahui tentang pembentukan senyawa ion masih sangat sederhana, yaitu hanya pada bagian Na melepas elektron dan Cl menangkap elektron. Setelah mempelajari reaksi redoks dan diberikan contoh reaksi di atas, persamaan reaksinya juga sederhana, hanya merupakan reaksi total. Namun, di samping itu pada kompetensi dasar lain, Anda belajar tentang energi ionisasi dan afinitas elektron yang sebenarnya merupakan bagian dari pembentukan senyawa ion, dalam hal ini NaCl. Konsep reaksi lengkap di atas telah Anda pelajari semua, namun terpisah-pisah dan terlepas, belum pernah atau jarang konsep-konsep itu dikaitkan satu sama lain. Pada kesempatan ini, marilah kita bahas hal itu, kita ikuti penalarannya berdasarkan alur perubahannya. Dengan demikian kita berupaya mengintegrasikan konsep-konsep yang terpisah, dengan harapan nalar kita menjadi lebih menguat. Sehingga kecenderungan menghafal dapat makin berkurang.
Irisan kecil padatan Na dimasukkan ke dalam wadah yang berisi gas khlor. Kedua unsur itu akan bertumbukan, yang terjadi saat mereka bertumbukan adalah mereka masing-masing berupaya untuk melepaskan diri dari ikatan yang ada untuk saling berikatan membentuk senyawa NaCl yang lebih stabil.
Logam Na(s) memiliki ikatan logam, yaitu ikatan antara ion-ion positif natrium dengan arus elektron yang mengikat kuat menjadi kristal logam. Ion Na+ ini tidak dapat langsung bereaksi selama elektronnya mengikat erat dia dengan teman-temannya yang lain. Maka Na(s) yang terjejal rapat itu, pada bagian permukaan yang tertumbuk Cl2, melepaskan diri dari temannya dengan membawa elektron valensinya kembali, membentuk atom Na dalam keadaan sendiri atau sebagai Na(g).
Pada saat yang bersamaan, Cl2(g) mengalami pemutusan ikatan menjadi atom-atomnya, Cl(g). Pada waktu itulah selagi masing-masing atom sendirian, terjadi perpindahan elektron dari Na(g) ke Cl(g). Na(g) memerlukan energi ionisasi sedang Cl(g) melepaskan energi yang dinamakan afinitas elektron. Jadilah ion-ion Na+(g) dan Cl-(g) yang dengan segera merapat (menyublim) menjadi NaCl(s) tanpa melalui fase cair. Sejumlah energi kisi dilepaskan, NaCl(s) terjaring oleh kisi kristal membentuk kristal ion. Hati-hati memahami mekanisme reaksi di atas. Kejadian itu cepat sekali berlangsungnya. Pada saat kita mereaksikan, NaCl(s) langsung terbentuk.
d.Pemanenan hydrogen
Meningkatnya kebutuhan dunia akan bahan bakar, sementara stok bahan bakar fosil tidak dapat bertambah, membuat penelitian mencari sumber bahan bakar alternatif makin intensif. Salah satu alternatif tersebut adalah hidrogen sebagai sumber energi yang ramah lingkungan dan tanpa polusi. Saat ini hidrogen paling banyak diproduksi dari gasalam (48 %), dan merupakan elemen paling ringan di dunia (berat atom = 1 g/mol), sehingga kemampuan difusinya sangat tinggi.
Hidrogen dapat juga digunakan sebagai bahan bakar reaktor fusi (masih tahap pengembangan), dan sebagai sumber bahan baku pembuatan HidroCarbon (BBM Sintetis). Kendala utama untuk produksi hidrogen adalah sumber gas alam sendiri adalah sumber energi yang tak dapat diperbaharui, cadangannya pun semakin menipis, dan harganya terus naik.
Ternyata ada solusi untuk memecahkan masalah tersebut. Salah satu cara yang lazim dipakai untuk menghasilkan hidrogen adalah dengan elektrolisis air. Hasil yang akan diperoleh dari proses ini adalah gas hidrogen di bagian katoda, dan gas oksigen di bagian anoda. Meskipun demikian, elektrolisis masih terkendala oleh biaya yang sangat mahal karena proses ini menghabiskan energi listrikyang sangat besar, sehingga tidak komersial. Dengan demikian perlu dicari cara lain untuk menghasilkan hidrogen yang dapat bernilai komersial. Cara yang dapat dipakai yaitu dengan menggunakan Natrium/Sodium.
Natrium banyak tersedia dan melimpah jumlahnya di lautan sebagai garam NaCl. Natrium termasuk golongan logam alkali yang sangat reaktif, biaya produksi natrium pada tahun 1997 adalah US$ 0.30/kg – US$0.45/kg, cukup murah. Pada kondisi standar, logam natrium jika direaksikan dengan air akan menghasilkan gas hidrogen dengan reaksi sebagai berikut:
2Na + 2H2O → 2NaOH + H2 ………………….(1) Eksotermal
2H2 + O2 → 2H2O ……………………………….(2) Autoignition
Reaksi tersebut bersifat sangat eksotermal (menghasilkan panas), sehingga gas hidrogen secara otomatis akan terbakar, ini disebabkan karena gas hidrogen mengalami proses autoignition akibat perpindahan panas dari reaksi ke lingkungan. Dari hal tersebut ternyata gas hydrogen dapat dipanen.
Gas Hidrogen memiliki Flammability Limit dengan kisaran volume 4 – 75 % di udara, dan memiliki Autoignition Point pada suhu 585 0C, reaksi pembakaran selalu membutuhkan oksigen, begitu juga dengan Hidrogen, dengan reaksi sebagai berikut:
2H2 + O2 → 2H2O ……………………………….(3)
Proses Autoignition Hidrogen pada reaksi Natrium dengan Air dapat dicegah dengan cara menyingkirkan oksigen pada sistem tertutup sehingga Flammability Limit dan Autoignition tidak berlaku yaitu dengan metode ruang hampa dan penggurahan oleh gas inert (Nitrogen).
Nitrogen memiliki titik didih pada -195.79 0C, pada kondisi cair nitrogen memilki temperatur di bawah – 195.79 0C. Pelepasan gas nitrogen secara cepat ke dalam sistem tertutup dapat menggantikan posisi oksigen. Pada kondisi standar, suhu kamar 25 0C, Nitrogen cair akan mendidih dengan sangat cepat, tuangkan nitrogen cair (temperatur < – 196 0C) dari tabungnya ke dalam wadah logam (yang bersuhu + 25 0C), maka nitrogen cair akan mendidih dengan sangat cepat namun tidak lama, bisa ditambahkan air agar lebih lama mendidihnya, gas inilah yang akan dimanfaatkan untuk menyingkirkan oksigen (purging).
Pada saat kondisi sistem (tertutup) telah dihampakan (vacum), segera isi dengan gas nitrogen, kemudian reaksikan natrium dengan air, akan menghasilkan gas hidrogen dan natrium hidroksida (produk samping). Karena berada pada kondisi inert, reaksi autoignition hidrogen dapat dicegah, sekalipun efek eksotermal terus terjadi. Karena berat atom hidrogen = 1, maka hidrogen akan selalu mengisi ruang yang paling atas, difusifitasnya pun sangat cepat, tidak lupa juga hidrogen harus melewati kondensor agar temperaturnya turun (akibat proses eksotermal), setelah dingin dapat dikumpulkan dan dikompresi lalu hidrogen siap dipanen, sehingga proses ini memungkinkan untuk dilakukan.
Cara lain untuk menurunkan efek eksotermalnya, sebelum direaksikan natrium dicelupkan dulu ke nitrogen cair ( < – 195.79 0C), baru kemudian direaksikan dengan air, diharapkan efek eksotermalnya sedikit berkurang karena temperatur natrium yang berada pada kisaran – 195 0C.
Selain itu produk sampingnya yang berupa NaOH memiliki nilai jual juga sebagai basa kuat yang sangat diperlukan sebagai bahan baku beberapa industri hulu, sehingga proses ini sangat menguntungkan.
e.Rahasia pembuatan hot ice
Hot ice adalah cara pembuatan ice dengan sekejap dengan memanfaatkan pelepasan kalor dari reksi natrium asetat dengan air. Untuk jelasnya kita lihat prosedur pembuatan hot ice tersebut.
Persiapan :
1.Persiapkan Sodium Asetat, sering disebut Natrium Asetat
(bisa dibeli di toko kimia, rumus kimianya : NaC2H3O2)
, air, dan panci.
2.Rebus air sampai hampir mendidih, tambahkan sodium asetat, aduk hingga larut.
3.Jika sudah larut, masukkan air ke dalam gelas. Pastikan endapan Sodium Asetat tersaring dengan sempurna.
4.Masukkan gelas berisi larutan tersebut ke dalam kulkas (bukan di dalam freezer.
Prosedur :
1.Saat akan melakukan performance, tuang larutan tersebut ke dalam botol/ gelas.
2.Sentuhlah permukaan larutan tersebut dengan tangan anda/ tangan sukarelawan selama beberapa saat (kurang lebih satu menit, tergantung perbandingan antara sodium asetat dan air). Dalam sekejap, air tersebut akan membeku menjadi es.
Penjelasan Ilmiah Secara Singkat dan Sederhana :
1.Reaksi proses Hidrasi (penambahan air) yang terjadi pada Sodium Asetat adalah reaksi eksotermis, artinya reaksi yang membebaskan kalor dari sistem (larutan) ke lingkungan. Inilah yang menyebabkan es yang terbentuk agak terasa hangat walaupun larutan baru saja didinginkan di lemari es.
2.Bentuk padat sodium asetat "menyerap" tiga molekul air sehingga membentuk senyawa baru bernama Sodium Asetat Trihidrat.
Berikut rumus kimianya :
NaC2H3O2(s) + 3H2O (l) ---> NaC2H3O2-3 H2O (s) + panas
Manfaat natrium dalam kehidupan sehari – hari
Na dulunya banyak digunakan untuk pembuatan TEL (Tetra Ethyl Lead), yaitu untuk menaikkan bilangan oktan bahan bakar, tetapi sekarang tidak lagi karena mengandung racun yang berbahaya bagi lingkungan. Na juga digunakan untuk pengisi lampu penerangan di jalan maupun di kendaraan. Hal ini dikarenakan emisi warna kuningnya yang mampu menembus kabut dan dapat digunakan juga sebagai cairan pendingin pada reaktor atom.
1.NaOH disebut soda api. Digunakan sebagai bahan baku untuk pembuatan sabun, detergen, kertas, dan serat rayon.
2.Na2CO3 (Natrium karbonat) dikenal dengan nama soda. Digunakan dalam industri kaca, melunakkan air sadah dan menghilangkan noda minyak.
3. NaHCO3 (Natrium bikarbonat) juga disebut soda kue. Digunakan untuk pembuatan kue.
4.C5H8NNaO4 (Natrium Glutamat), digunakan sebagai penyedap makanan.
5.NaC6H5CO2 (Natrium Benzoat), digunakan sebagai pengawet makanan dalam kaleng.
