Air and combustion

Air and combustion

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  Air and Combustion By, RiyaShah
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  Contents…  Air, whatis it?  Properties of it  Uses of it  Components of it  Fractional distillation  Defining Combustion  Types of it  Causes of combustion  Effects of combustion  Prevention of combustion  Bibliography
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  Air, what isit?  Air is a mixture of many gases. Air is a precious resource, present in the earth, that most of us take for granted. The air supplies us with oxygen, which is essential for us, to live and operate properly. Pure air is a mixture of several gases that are invisible and odorless. The air has 78% of nitrogen and 21% of oxygen.  Fact: It’s true that adults breathe in about 10-20 cubic meters of air every day. That’s about 20,000 breaths. Children breathe almost twice that amount because they’re smaller, and their respiratory systems are still growing.
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  Properties of it It is colourless  It is odourless  Air is a mixture of gases so its atoms spaced out.  The weight of dry air(no moisture content) at 0 deg C and under a normal atomospheric pressure of 1013 milibar is 1.293 kg/m3.  The weight of dry air (no moisture content) at 0 deg C and at a pressure of 1000 mbar (1 Bar) is 1.275 kg/m3.
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  Uses of it Air contains oxygen, which is essential for life on earth, as it is used for respiring.  Air supports combustion. The oxygen present in air helps a lot in burning. And we need that to burn fuel for cars, coal for food etc. And if nitrogen wasn’t present in the air, then even small fires would have turned into huge explosions! We should be very thankful that (1) nitrogen reduces the activity of oxygen and (2) nitrogen is present in the air in a much higher number as compared to oxygen.  Compressed air is used to fill air in tyres.
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  Continued…  Nitrogen isessential for the growth of plants. They absorb it directly from the air or soil.  Moving air, i.e. wind, helps to move boats and windmills and helps in the dispersal of seeds.
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  Components of air Airis made up of a variety of gases. These include…  Nitrogen(78%)  Oxygen(21%)  Argon, Carbon dioxide, water vapour and other gases present on earth(1%)
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  Fractional Distillation  Fractionaldistillation is just basically the separation of a mixture, into its components. As in you separate the compounds by heating them to their boiling points, at then which at least one or more of the components of the compound will vaporize. Usually, the components boil with a difference of 25˚C or less, but if it is greater than that, than you use simple distillation. This process can be used to separate the components of air.
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   Distillation inair happens Fractional distillation in air o Fractional distillation in air happens practically the same way as in petroleum and other substances. o But, as air is a gas already, they first freeze it, and then they slowly heat up the temperature so that each gas will rise up according to their boiling points. o And after they rise up, they get collected.
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  Now, what’s combustion? Combustion is a chemical process in which a substance reacts with oxygen and producing energy which is in the form of heat and light.  Combustible substances  Combustible substance: Substances that burn easily or catch fire easily are called combustible substances.  The combustible substances are:  Paper  Clothes  Wood  LPG  Coal  Petrol
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  Types of it On the basis of speed of combustion  Rapid combustion:- Rapid combustion is when the substance burns rapidly and produces heat and light. For eg: Ignition of a gas burn  Spontaneous combustion:- Spontaneous combustion is when the substance suddenly burning into flame. For eg : White phosphorus reacts with air.  Explosion combustion:- Explosion combustion is a sudden reaction with the production of heat, light and sound. For eg: Fire crackers.  On the basis of availability of oxygen  Complete combustion: Complete combustion is when the reaction takes place in the total availability of oxygen. eg:- Carbondioxide  Incomplete combustion: Incomplete combustion is when the reaction takes place when there is not enough availability of oxygen. eg:- Carbon-monoxide
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  Causes of combustion A substance which has low ignition temperature begins to release heat. This can occur in several ways like oxidation (by presence of moisture and air).  The heat is unable to escape, and the temperature of the material rises and then rises more above its ignition temperature.  Combustion begins if sufficient oxygen is present (even fuel can be present for combustion to take place).
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  Effects of combustion Combustion can cause irritation/annoyance(e.g. noise, smoke)  It can lead to damage in property  It can lead to a lot of injury to people and also lead to death.  Greenhouse gas emissions released to the atmosphere that contribute to global warming
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  Prevention of combustion Agricultural products: Spontaneous heating in agricultural products can be prevented by control of moisture. Proper drying and sufficient airflow will limit heating. The temperature should be checked regularly.  Oily Rags: Rags that have absorbed oils such as linseed oil or turpentine should be kept in well-covered metal cans and thoroughly dried before collection or transport so that it cannot lead to combustion.
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  Bibliography  "About AntiqueCars, Fire, and Fire Extinguishers." Antique Cars, Fire, and Fire Extinguishers. Web. 16 Feb. 2015. <http://www.allpar.com/fix/fuel/fires.html>  "Spontaneous Combustion." Wikipedia. Wikimedia Foundation. Web. 16 Feb. 2015. <http://en.wikipedia.org/wiki/Spontaneous_combustion>.  "Spontaneous Combustion or Chemical Reaction." Spontaneous Combustion or Chemical Reaction. Web. 16 Feb. 2015. <http://www.nfpa.org/research/reports-and- statistics/fire-causes/chemical-and-gases/spontaneous-combustion-or-chemical- reaction>  Web. 16 Feb. 2015. <http://webserver.dmt.upm.es/~isidoro/bk3/c15/Environmental effects and hazards in combustion.pdf>.  "Combustion." Combustion. Web. 16 Feb. 2015. <http://www.grc.nasa.gov/WWW/k- 12/airplane/combst1.html>.  Helmenstine, Ph.D. "Combustion Definition - Chemistry Glossary." Web. 16 Feb. 2015. <http://chemistry.about.com/od/chemistryglossary/g/combustiondefinition.htm>.  "Properties of Air." :. Web. 28 Feb. 2015. <http://www.arca53.dsl.pipex.com/index_files/propair.htm>.
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  Thank you