Chemistry

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Combustions


The combustion of butane



1) Complete combustion of butane

The gas inside of a lighter is butane therefore the ignition of a lighter provides a simple mean to study combustion of butane.

To analyze this combustion some tests are realized:

- If a lighter flame is put in a test tube, its walls are covered with condensation. We can verify that this condensation is made of water using anhydrous copper sulfate ( it should turn blue ).
Combustion continues a few moments and then the flame goes out.

- The test tube is then used to collect gases produced during the combustion. In this tube the lime water test is positive.

The combustion therefore produces water and carbon dioxide and It consumes dioxygen and butane.

Reactants are butane and oxygen
Products are carbon dioxide and water


Chemical reaction::
                     Butane + dioxygen   →      carbon dioxide + water

It is said that such combustion is complete combustion.

2) Incomplete combustion of butane

If there is not enough dioxygen to burn all the butane then combustion is incomplete:
In addition to other products it appears a black solid compound ( carbon ) and a gaseous compound colorless, odorless and very toxic ( carbon monoxide )


Chemical reaction is then :
Butane + dioxygen     →    carbon dioxide + water + carbon + carbon monoxide

Comment: butane as well as methane, ethane and propane are natural gases. They burn producing water and carbon dioxide, moreover these combustions may also be incomplete.





Science class

Mechanics lessons
Water

Water on Earth
Changes of state in the nature: the water cycle
Water in human body
Test for water
Properties of water in different states

States of matter

States of matter and its changes
Boiling water
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Filtration
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Distillation
Chromatography
Dissolving a solid in water
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Miscibility in water

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Mass of a liter of water
Volumetric mass density

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Atoms
Composition of molecules
Constituents of the atoms
The electrical neutrality of the atom

Combustions

Basics of combustion
The combustion of carbon
The combustion of butane

Atoms and chemical reactions

Chemical reactions
Chemical equations
Law of conservation of mass
Chemical synthesis

Metals

Most common metals
How to distinguish metals ?

Corrosion of metals
Electrical conductivity of solid materials
Electrons and free electrons
Electric current in metals

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The conductivity of aqueous solutions
Aqueous solutions and ions
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Formation of ions
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Acidic and basic solutions

pH of aqueous solutions
Ions in acidic and basic solutions
Dilution of acids and bases
Composition of hydrochloric acid
Chemical reaction between iron and hydrochloric acid

Electrochemical cells and chemical energy

Chemical reaction beteween a copper sulphate solution and zinc
Copper sulfate and zinc battery
Basics of electrochemical cell


        










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