Chemical Changes: Combustion

Combustion

What is combustion? It is the burning of a complex sequence of chemical reactions between a fuel and an oxidant accompanied by the production of heat or both heat and light in the form of either a glow or flames. In a complete combustion reaction, a compound reacts with an oxidizing element, such as oxygen or fluorine, and the products are compounds of each element in the fuel with the oxidizing element.

Rapid combustion is a form of combustion in which large amounts of heat and light energy are released, which often results in a fire. This is used in a form of machinery such as internal combustion engines. Sometimes, a large volume of gas is liberated in combustion besides the production of heat and light. The sudden evolution of large quantities of gas creates excessive pressure that produces a loud noise(explosion). Combustion need not involve oxygen. Hydrogen burns in chlorine to form hydrogen chloride with the liberation of heat and light characteristic of combustion.

In complete combustion, the reactant will burn in oxygen, producing a limited number of products. When a hydrocarbon burns in oxygen, the reaction will only yield carbon dioxide and water. When a hydrocarbon or any fuel burns in air, the combustion products will also include nitrogen. When elements such as carbon, nitrogen, sulfur, and iron are burned, they will yield the most common oxides. Carbon will yield carbon dioxide, nitrogen will yield nitrogen dioxide ,sulfur will yield sulfur dioxide and iron will yield iron oxide. However, a complete combustion is almost impossible to form. In reality, a wide variety of major and minor species will be present. For example, the combustion of methane in air will yield, in addition to the major products of carbon dioxide and water, the minor side reaction products carbon monoxide and nitrogen oxides.

Incomplete combustion occurs when there isn't enough oxygen to allow the fuel to react completely with the oxygen to produce carbon dioxide and water, also when the combustion is quenched by a heat sink such as a solid surface or flame trap. When a hydrocarbon burns in air, the reaction will yield carbon dioxide, water, carbon monoxide, pure carbon (usually in the form of soot or ash) and various other compounds.

Combustion is used in everyday's life. Whether is it cooking, running of machines, running factories, the use of combustion is everywhere.

Chemical Changes: Single Displacement

Single Displacement

In this type of reaction, one element replaces another in a compound. This happens in two situations:
1. When a metal displaces a metal
2. A non-metal displaces a non-metal

In most single displacement reactions there is an element and an ionic compound as reactants.

The general pattern is:

A + BC --> AC + B

element A displaces element B

A and B are elements

BC and AC are compounds

Double Displacement

Double Displacement is a biomolecular process involving the exchange of bonds between the two reacting chemical species, which results in the creation of products with similar or identical bonding affiliations. To illustrate, consider two chemical species, AB and CD, which react to give AD and CB:

AB + CD → AD + CB
These chemical species can either be ionic or covalent.

A neutralization reaction is a specific type of double displacement reaction. Neutralization occurs when an acid reacts with an equal amount of a base. A neutralization reaction creates a solution of salt and water.

On the next post, I will be talking about combustion.

Chemical Changes: Decomposition

Decomposition

Chemical decomposition is the seperation of a chemical compound into elements or smaller compounds. It can be defined as the opposite of a chemical synthesis, though it would be wrong to say that decomposition is the direct opposite of chemical synthesis. Chemical decomposition is often an undesired chemical reaction, though not always. The stability that a chemical compound ordinarily has is eventually limited when exposed to extreme environmental conditions like heat, radiation, humidity or the acidity of a solvent. The details of decomposition processes are generally not well defined, as a molecule may break up into a host of smaller fragments. There are 2 types of decomposition reactions, thermolysis and electrolysis

Thermolysis, also known as thermal decomposition, is defined as a chemical reaction in which a chemical substance breaks up into at least two chemical substances when heated. The reaction is usually endothermic as heat is required to break chemical bonds in the compound undergoing decomposition. The decomposition temperature of a substance is the temperature at which the substance decomposes into smaller substances or into its constituent atoms. The following video will show the effects of thermal decompositon.

Electrolysis is the passage of an electric current through an ionic substance that is either molten or dissolved in a suitable solvent, resulting in chemical reactions at the electrodes and separation of materials.The key process of electrolysis is the interchange of atoms and ions by the removal or addition of electrons from the external circuit. The required products of electrolysis are in some different physical state from the electrolyte and can be removed by physical process. The following video shows elctrolysis of water.

Electrolysis - Break Water Into Hydrogen And Oxygen - For more of the funniest videos, click here

Having understand decomposition, i will be moving on to single displacement.

Chemical Changes: Synthesis

Synthesis

As said in the video, a synthesis reaction is where "two or more substances combined to form a single product". A synthesis reaction is the formation of complex chemical compounds from simpler ones. Many substances that are important to daily life are obtained from synthesis. Chemists synthesise chemical compounds that occur in nature to gain better understanding of the structures. Synthesis also enables chemists to produce compounds that do not form naturally for research purposes.

Chemical compounds are made up of atoms of different elements, joined together by chemical bonds. A chemical synthesis usually involves the breaking of existing bonds and the formation of new ones. Synthesis of a complex molecule may involve a large number of individual reactions in sequence from available starting substances to the desired end product. Each step usually involves reaction at only one chemical bond in the molecule.

The reactions involved in chemical syntheses usually involve at least two different substances. However that may not always be the case. Some molecules will change into others solely under the effect of heat or exposure to radiation. When two or more different substances interact, they need to be brought into close proximity with one another. This is usually done by carrying out the syntheses with the elements or compounds in their liquid or gaseous states.

After defining synthesis, you may asked, how is synthesis important? Where is it used? Well, one of the most commonly known is photosynthesis. The following video will explain what is photosynthesis.

Photosynthesis is an important biological process on earth. By taking in carbon dioxide and giving out oxygen, it has transformed the world into the hospitable environment we know today. Directly or indirectly, photosynthesis fills our food requirements and many of our needs for fibre and building materials. The energy stored in petroleum, natural gas and coal all came from the sun via photosynthesis, as does the energy in firewood, which is a major fuel in parts of the world.

You see, synthesis is not as foreign to us as many will think. Synthesis is also used to mass produce many products in the industry. On my next post, I will be writing and sharing more knowledge on decomposition. Hold your thoughts until then.

CHem REsearch TOpic

What are the different types of chemical changes and how are they used in real life?

This is my research topic. I decide to do this topic because I do not really understand what is chemical changes. It would also be interesting to know how they are used to benefit us in real life.

Prior to my research, I found out that other than chemical changes, there is also a physical changes. Let me define what is chemical changes. Chemical changes refers to bonds broken and new bonds formed between different atoms. The breaking and forming of bonds takes place when particles of the original materials collide with one another. Simply put, Chemical change is observed when the composition of a substance changes.

However, physical change is different to chemical change. Physical changes occur when objects undergo a change that does not change their chemical nature and only involves in changing of physical properties. Simply put, a physical change does not change the composition of a substance. An example would be water. Water in itself is in liquid form. However when it freezes, it state changes into ice. Though it state changes, when it melts, it turns back into water again. This shows that there is no change to the compositon of the water even though it state changes.

Having define what is chemical change and the difference between chemical and physical change, I have also researched on the types of chemical reaction briefly. I would be focus on the 5 main types of chemical changes, mainly synthesis, decompositon, single displacement, double displacement and combustion. I found a video on the the following types of chemical changes and hope you enjoy it.

Now after viewing this video, we now have a basic understanding of the types of chemical changes. But a lot of questions are left unanswered. How did the two substances reacted with each other? Why did they react like that? My next post, however, will try to answer questions asked on synthesis.

Conclusion+Reflection+AOB

Reflection

Now, I know that polluted water is define as one or more substances that have been built up in water bodies such as lakes, rivers, oceans and groundwater to an extent such that it cause problems and are harmful to organisms and plants. Water pollution comes from many sources, mainly point source and non-point source. There are many effects of water pollution, from water borne diseases to marine debris to thermal pollution. There are many solutions to solve the issue of polluted water. Most of the time being whether people wants to co-operate or not. There are a few interesting facts that i learned when doing my research. I did not put in my post, but here are 2 interesting facts I learned. One, Asian rivers are the most polluted in the world. They have three times as many bacteria from human waste as the global average and 20 times more lead than rivers in industrialized countries. I felt quite hard to believe. In Singapore, everyone has accessed to clean water, and the dirtiest water was most probably from the toilet. I was shocked and surprised to learn that water in our neighboring countries was that polluted. The figures were truly appalling. Number of bacteria from human waste is a massive number, but 3 times? That is really, really dirty. The second fact I find interesting is, pollution of freshwater (drinking water) is a problem for about half of the world's population. Each year there are about 250 million cases of water-related diseases, with roughly 5 to 10 million deaths. Again, I am reminded about how fortunate I am living in Singapore. Clean water was available anywhere, but water is a problem for half the world's population. When we use water, we do not think how much is used, but for the people who needed the water desperately, every drop of fresh water for them is put to good use. There were indeed many problems when I started researching on this topic. The first problem was, obviously, what topic should I research on. After quite a long time of thinking and penning down ideas, I realised that I should do on a topic which has not been under much media, but a serious problem. I came upon this topic when I was looking at running water from tap. Water come so readily in Singapore, with just a twist of the tap, clean water is flowing immediately. I realised that there are problems in the world related to water, and decided to do this topic. After this whole research, something that kept bothering me was, people in Singapore are still wasting water. I felt bad that even though I know about the problems the world is facing with water, I could not do anything to help. My only hope is that through my journal, I can raise awareness of people and hopefully stop people from wasting water.

Reference:
http://en.wikipedia.org/wiki/Water_pollution
http://www.geocities.com/kamil_pollutionpage/WaterPollution.htm
http://www.explainthatstuff.com/waterpollution.html
http://www.grinningplanet.com/2005/07-26/water-pollution-facts-article.htm

Glossary:
1.Degrade-to break down
2.Zooplankton-the aggregate of animal or animallike organisms in plankton, as protozoans.
3.Sanitation-the development and application of sanitary measures for the sake of cleanliness, protecting health, etc.
4.Alzheimer's disease-a common form of dementia of unknown cause, usually beginning in late middle age, characterized by memory lapses, confusion, emotional instability, and progressive loss of mental ability.

The following words defintion is from dictionary.com

That is it for biology.

Water Pollution...No Way to Stop?

The answer is "NO". It is possible to stop water pollution. There are hundred and one ways for solution to water pollution. Even as simple as picking up a piece of litter before it is disposed down the drain. Why then, the problems arising from water pollution does not stop, but continue to persist on? Well, good starts are not always accompanied by good follow through. The first solution to stop water pollution would be the simplest. Enforce strict laws. However, this is usually done at the expense of the country economy, therefore it will not apply to all. Beyond laws, there are some practical water pollution solutions that can be implemented by society and of course, you.

Reducing Nutrient and Pesticide Pollution

There are several ways to reduce nutrients and pesticide pollution. One way is to encourage smart agricultural practices. Right-sizing applications of fertilizer and using of modern techniques can help keep polluted runoff from entering the drains and streams. The other way is to reduce urban runoff of lawn fertilizers and pesticides. Although fertilizers and pesticides appears to be helping your lawn, much of their volume is washed by rain or blown by air to nearby drains, streams, ponds, and rivers. They also will degrade the soil over time, causing more reliants on chemicals. The other way is to persuade people who drive to drive less. Nitrogen deposition from air pollution can be a big part of the nutrient pollution problem. How much people drive, how large their vehicle is, and many other factors play a part in how much pollution people leave behind without thinking.

Stopping Deforestation

A healthy forest is like a sponge, it soak up the rains when they come, holding the water and filtering it before it makes its way to nearby water bodies. When all the trees are cut down. the forest ecosystem dies and can no longer perform this service. Rain water rushes directly into water bodies, flowing over exposed soil, picking up and carrying sediment pollution into nearby water bodies. Support healthy forests by supporting efforts to ban forest clearing, making smarter lumber and paper choices for yourself and implementing methods to save paper.

Reducing Pollution from Oil and Petroleum

We cannot deny the fact that large amount of oil will naturally seeps into ocean from underground sources, however marine creatures in the area would have a long, long time to adapt to it. Human-caused petroleum pollution invariably happens in much more sensitive areas, often with disastrous consequences. The solution to this type of water pollution is to stop letting so much oil and oil byproducts get into the water in the first place. Indeed, we must reduce, or simply stop the occurrences of oil spills; but more importantly, we must reduce the amount of petroleum pollution getting into water bodies from non-point sources.

Some of examples of how governments and corporations can respond to petroluem pollution are to tightening regulations governing maintenance and inspections of commercial ships, motor boats, and recreational water craft, which can leak oil and fuel into the water. The other way is requiring filtration ponds and natural buffer zones around roads and parking lots to help keep runoff contaminated with oil and gas drips from getting into waterways.
Now as individuals, we can encorage people who drive to drive their vehicle less and maintain their your vehicle more.

Reducing Mercury Emissions

The solution to mercury pollution in our waters is to solve the mercury pollution problem coming from the land. In many countries, coal-burning power plants are the largest human-caused source of mercury emissions. Other sources of mercury pollution are chlorine production facilities and municipal and hazardous waste incinerators. Predictive models show that reducing mercury emissions to the air will reduce mercury pollution in water and the subsequent contamination of fish.

Cleaning Chemical Pollution

There are a few water pollution solutions we as consumers and citizens can implement when it comes to chemicals, the most simplest being buying organic food. Organic food do not require pesticides and other chemicals for it to grow. Another way is to start buying "green" household cleaners and personal care products and stop all use of chemical pesticides around your house.
Disposal of old paint, varnish, or other DIY chemicals should be done in the least dangerous manner. It is best to check with local government's environment or public works office to find out the safest way to do so.

Now after learning about the solution, my research has come to an end. Through all this post, we learnt that what is water pollution, effects of water pollution and finally about the solution to water pollution. Hopefully you have learnt as much as I do. Thank you!

We need to preserve the quality of our water, if not we will never get to enjoy this

anymore.

Water Pollution Effects

Hi I am back. Decided to do this before midnight so as to post by midnight. Anyway, this post will be more on the effects of water pollution. It will mainly be on chemical pollution, while touching a little on thermal pollution.

Chemical Pollution

Years passed, chemicals in water do not. Many types of chemicals have gotten into the water bodies and it is not stopping. Chemical water pollution typically occurs because
1.Chemicals were dumped into water intentionally.
2.Chemicals seeped into water bodies because of broken pipes or spoilt storage tanks.
3.Chemicals got into water bodies because of industrial accidents.
4.Chemicals were leached out of contaminated soil.

It's is hard to document the effect of every chemical that has polluted our water, however it is easy to note that
1.Severe chemical spills and leaks into our water bodies have an immediate effect on marine life.
2. A lower-level chemical pollution has problems manifesting over a long period of time and sometimes being difficult to link directly to the water pollution.
3.The human effects of chemical pollution in water can generally be viewed the same as any other form of chemical.
There are, however, a few broader categories of chemicals related to water pollution effects.

Pesticides

Pesticides are carried by rainwater runoff from farms and lawns into the nearest creeks and streams, ultimately landing into our water bodies. Occasionally they are intentionally sprayed into waterways as part of a pest-control effort. Just like what I see across the school, where the pesticides are sprayed to kill mosquitoes.

Pesticides have been found in wellwater in countries such as India, Israel, Japan and Australia. US. Pesticide contamination of drinking water is a particular problem in rural agricultural areas where alot of pesticides are used and drinking water supplies come directly from groundwater without treating. Pesticides can moved via water into the food chain as well, ultimately being consumed by humans and animals as food.

The general health effects on humans, pesticides can affect and damage the nervous system, casue liver damage, damage the DNA and cause a variety of cancers and cause reproductive and endocrine damage. It can also cause other acutely toxic or chronic effects.

Oil and Petroleum Chemicals

Ever heard of oil spills? When oil gets into the water bodies, components of the oil are degraded and dispersed into the water, while other components are more resistant and can persist for many years, especially in shallow waters with muddy sediments.

Oil causes big problems for aquatic animals. Exposure to oil or its chemicals can alter the ecology of aquatic habits and the physiology of marine organisms. Oil can also leak into marsh and sub-tidal sediments and lurk there for decades affecting life forms that live near the sediments.

The Exxon Valdez oil spill is one of the worst man-made disaster that ever happened in history.(check your history textbook if you do not believe). 20 years after this oil spill happened, the effects of the oil spill still persisted today. The oil has degraded and dispersed in small quantities below the surface in the coarse sediments, out of reach of the waves and sunlight needed to break down the oil constitutes. Studies have found that marine creatures suffered high mortality for years after the spill because they consumed food contaminated by the oil or swallowed the oil directly.

Mercury

Mercury gets it way to our water bodies through air pollution from power generation from coal, garbage incineration, recycling of older automobiles and some types of mining. In the water, mercury is changed to methylmercury by certain bacteria, after which it moves up the food chain of fish gobbling each other up. Because organisms tends to store mercury in their body, the concentration of mercury up the food chain gets higher and higher, in the end landing onto someone's dinner.

The effects of mercury is particularly scary. Children and fetuses especially. They are most at risk because they are still growing. Exposure to mercury at such a young age can cause neurological problems, including slower reflexes, learning deficits, delayed or incomplete mental development, and brain damage. Adults can be badly affected by mercury too. Mercury can cause central nervous system effects like Parkinson's disease, and Alzheimer's disease.Heart diseases are also affilated with it, and in severe cases, causing death or irreversible damage to the brain.

Thermal Pollution

(btw this is not part of chemical pollution)

Discharging heated water from a power plant into a river directly without fist cooling could cause problems for marine organisms used to having their water staying at a specific temperature. Fishes and other organisms adapted to a particular temperature range can be killed from by the extra heat provided, and the heat can disrupt spawning and kill young fishes.

A warmer water temperature lowers the dissolved oxygen content in the water. And have you ever thought that why you breath in harder when you feel hot? Now since the warmer water causes the marine creatures to increase their respiration rates, they consume oxygen faster. All this increases aquatic organisms' susceptibility to disease, parasites, and the effects of toxic chemicals.

Now after learning so much about the effects of water pollution, we should see how to solve the problems of water pollution.

Until the next post, SEE YA!

In fact, STOP any of POLLUTION.

Effects of Water Pollution

On my previous post, we learn about water pollution and what causes. This post and the post after this, however, will be dedicated to the effects of polluted water.

Water Pollution Effects
Waterborne Infectious Diseases

Waterborne infectious diseases are one of the most serious effects of water pollution, especially to people living in developing countries, where there are little or no sanitation available. Waterborne diseases occur when micro-organism or parasites from contaminated water are transmitted to humans. These includes typhoid, intestinal parasites, and diarrheal diseases caused by bacteria.



However, that does not mean that people living in developing countries are free from waterborne diseases. Transmission of disease agents such as bacteria via contaminated but poorly treated municipal water is common. An estimated seven million Americans are taken ill by contaminated water every year.

Going to beaches may sound fun, but due to outdated monitoring methods of the water, beachgoers are vulnerable to rashes, pink eye, respiratory infections, diarrhea, vomiting, and many more illnesses.

Nutrient Pollution

Nutrient pollution... too much nutrients in water? WRONG! Nutrient pollution occurs when nutrients are leaked into coastal areas through agriculture and waste disposal. Nutrient pollution is one of the most widespread environmental problems in the coastal areas. Once nutrient pollution reaches the coastal zone, algae can grow at an incredible rate, which can have direct toxic effects and results in low-oxygen conditions.

Some kinds of algae are toxic. Overgrowths of these algae is dangerous. Zooplankton eat the toxic algae and begin passing the toxins up the food chain, affecting any organisms that are up the food chain. The outcome... illness and sometimes death. Non toxic algae can also cause many problems. It reduces water clarity, making it hard for marine creatures to find food and blocking the required sunlight for water plants to grow.

Even when the algae overgrowth dies, problems still arise. the algae decomposes, a process which uses oxygen from surrounding water. There are extreme cases where decomposition process takes enough oxygen out of the water that the oxygen level is way low to support marine lifes.



Marine Debris



It simply means trash in the ocean. Marine Debris is one of the most pervasive marine pollution problem. Debris includes trash and garbage thrown overboard by ships —plastic bottles and bags, styrofoam, etc. Marine creatures will swallow this trash items thinking it is food. For example, sea turtles will eat a plastic bag thinking it is a jellyfish. The bag can cause a blockage or even death.




Even lost or discarded fishing equipments can cause many problems. Line, ropes, nets and many other fishing gears can get entangled or wrapped around marine creatures, causing drowning.


Here's the good news and the bad news. Good news is, after many years of degradation at sea, plastic breaks up into smaller pieces. Bad news? The plastic has not biodegraded but rather has disintegrated into very small pieces. This means that tiny marine creatures near the bottom of the food chain are now digesting bits and pieces of plastic. How far up the food chain the stuff will go is still a ?.


On my next post, I am going to continue talking about effects of Water Pollution. A reminder to all.
PLEASE DO NOT TREAT OCEANS LIKE DUMPS, WHAT GOES AROUND, COMES AROUND.

Water Pollution...Huh?

What is Water Pollution?

Water pollution is defined in more ways than one. Usually, it means that one or more substances that have been built up in water bodies such as lakes, rivers, oceans and groundwater to an extent such that it cause problems and are harmful to organisms and plants. Usually, the substances built up in the water bodies, known as pollutants, are caused by human activities. This pollutants are discharged into water bodies with little or no treatment to it first. The pollutants could very quickly have an effect on the quality of the water in the water bodies. This affect the health of all the plants, animals, and humans whose lives depend on the river.

Simply put, when water in the water bodies are unfit for intended uses, water is considered polluted.

Point Source and Non-Point Source of Water Pollution

Point Source Pollution

Point source pollution refers to pollutants that enter the water bodies directly. The main sources are usually discharges from sewage and industries. Sewage contains human wastes and water that has been used for many uses, including bathing and washing of clothes. Industry puts three to four more times as many pollutants into water as all of our sewage systems do. Point source pollution can be monitored and controlled with technology, however, political issues can complicate things.
Non-Point Source Pollution

Non-point source pollution refers to contamination that does not originate from a single source. It is often a cumulative effect of small amounts of pollutants gathered from a large area through environmental changes. Some farmers use chemical fertilizer to help thier crops grow faster. Pesticides are also use to kill pests such as insects and weeds. Non-point source pollution occurs when rainwater carry these chemicals into streams, rivers and lakes, in turn affects aquatic life as those chemicals are harmful to the aquatic life. Non-point sources are much more difficult to monitor and control than point source pollution. Streams, rivers and lakes that are polluted are ususally the cause of non-point source pollution.

Simply put, anything that is not part of the water bodies, should stay out of the water.


Variety of Pollutants

Municipal Waste

Municipal waste refers to household waste or domestic waste, and are usually waste materials left from household sources that have not been separated out or sent for reprocessing. There are 5 main types of waste namely, Biodegradable waste, Recyclable, Inert waste, Composite waste and Domestic Hazardous waste. Although today the disposal of Municipal waste is by landfilling or landspreading, some of the waste are disposed through water bodies.

Industrial Waste

Industrial wastes are waste created from industry such as factories and power plants. Industrial waste are contains some of the most hazardeous waste, including Mercury, a toxic heavy metal which, when ingested, can cause serious neurological damage, particularly to developing fetuses, infants and children. Cadmium, produced by industries and mining which are very dangerous even in minute amounts, and Lead, when exposed may cause neurological impairments such as seizures, mental retardations and behavioral disorders.

Simply put, you do not want any pollutants in your water.

Now that we know more about water pollution, it is time to tackle the research question. On my next post, I will be talking about the effects of polluted water.

The research question

What problems did polluted water cause to the environment and organisms around the world?

That is my research question.
I linked it when i was thinking about the topic of ecology. Taking reference from wikipedia, ecology refers to interdisciplinary scientific study of the distribution and abundance of organisms and their interactions with their environment. So it leds me to think, humans have interacted with the environment for many years now, so, how did it affected other organisms and the environment itself? It then led me to find out what happen to the environment and organisms when something manmade, such as polluted water, gets into the ecosystem. This eventually led me to my question, what problems did polluted water cause to the environment and organisms around the world?

That is it for now. On the next entry, i will be focusing on exactly what is polluted water.


Reference
http://en.wikipedia.org/wiki/Ecology