Combustion is any chemical reaction in which a fuel, an oxidizable substance, reacts with an oxidizing substance, releasing energy, generally in the form of heat. … In the combustion in air there is therefore the formation of liquid or vaporized water, and carbon dioxide.
Why is combustion a chemical reaction?
Combustion is a chemical reaction that involves the oxidation of a fuel by a comburent (which is generally represented by the oxygen present in the air), with the development of heat and electromagnetic radiation, often including light radiation.
How can a chemical reaction be defined?
A chemical reaction is a process or transformation of matter that leads to the formation of new substances, products, deeply transforming the starting substances, the reactants. A chemical reaction is a process in which bonds are formed and / or broken between atoms of the same element or of different elements.
What are the products of combustion?
Combustion reactions can be complete if the oxidation of a fuel produces only carbon dioxide and water. If the amount of oxygen is not sufficient, incomplete combustion can occur, resulting in the formation of carbon monoxide and soot as well as carbon dioxide.
What is the difference between chemistry and physics?
Physical transformations are the transformations of the state of matter. The physical properties of matter do not derive from variations in its compositions. Chemical transformations are the transformations of the composition of matter.
What can be physical or chemical?
Physics also deals with the fundamental principles that explain matter and energy, and can study aspects of atomic matter, following concepts derived from the fundamental principles. Chemistry focuses on how substances interact with each other and with energy (e.g. heat and light).
What is meant by chemical and physical transformation?
The difference between a chemical and physical transformation is that a physical transformation causes a physical change in matter, does not generate new substances and is reversible, while a chemical transformation involves a change in the chemical composition, generates a new matter and is irreversible.
What does coal combustion produce?
In fact, the combustion of coal generates large quantities of carbon dioxide (CO2), more than oil and natural gas produce.
What is the main extinguishing action of the foam?
Foam is an extinguishing agent consisting of a solution in water of a foaming liquid. The extinguishing action of the foams occurs by separating the fuel from the comburent and by cooling.
What are class B fires?
Class B: liquid fires
Class B includes fires originating from highly flammable liquids such as petrol, hydrocarbons, alcohol, solvents, greases and mineral oils. In this context, the combustible material has a volume but not a shape of its own: consequently, its expansion must be contained.
What changes when the reactants are transformed into products?
A chemical reaction is a transformation of matter that occurs without measurable changes in mass, in which one or more chemical species (called “reactants”) modify their original structure and composition to generate other chemical species (called “products”).
What changes in the system make it possible to detect the formation of new substances?
The chemical reactions of matter (also called chemical transformations) are irreversible transformations in which new substances are formed; they are transformations that affect the nature of the particles of substances, modifying them and thus allowing the formation of new substances.
When does a chemical reaction occur?
Chemical transformations, or chemical reactions, are those where a material is transformed into a new type of material, with different chemical properties. Burning coal or a piece of wood, rusting iron in the air, or digesting food are examples of chemical transformation.
What are the reactants and what are the products in the wood combustion reaction?
In combustion, the products that react are the fuel (wood) and the oxygen contained in the air whose masses add up to react and give rise to the products of combustion which are fumes and ashes whose added masses are equal to the masses that have reacted.
How to explain combustion to children?
Combustion is, from a chemical point of view, a very rapid oxidation reaction in which several substances (fuels, in fact) combine with the oxygen in the air (the comburent). This process also generates light and heat.
What gives rise to a fire?
The oxidizing agent par excellence is oxygen present in the air, but other substances can also act as oxidizing agents (eg ozone, hydrogen, etc.); trigger: the reaction between the fuel and the comburent is not spontaneous but occurs by an external trigger.
What is the best extinguishing agent for flammable liquids?
Carbon dioxide is an “excellent extinguishing agent for class ‘B’ and ‘C’ fires (liquid and gas fires) and for fires from live electrical equipment”. It can also be used on class ‘A’ fires (solid fires).
How can it be a foam?
A foam is a dispersion of a gas in a liquid, solid or gel medium. We speak in particular of liquid foam in the first case and solid foam in the second case. In some cases the foams have characteristics of colloidal dispersions.
How are foaming liquids composed?
They are foams composed of protein substances hydrolyzed with surfactant fluorocarbons and with the addition of stabilizers. The use of surfactants allows the formation of a liquid film essential for the effectiveness of the extinguishing.
What is not a fossil fuel?
A further 7% is derived from nuclear energy; in this regard it is noted that although uranium cannot be considered a fossil fuel, as an energy supplier it is part of the limited and non-renewable natural resources.
What does coal produce?
Coal is also used as an energy raw material for the production of synthetic fuels (coal liquefaction) and town gas (coal gasification). In addition to these uses, coal is used to generate heat in the home (heating) and for cooking.
What are the benefits of coal?
In countries with high poverty rates, coal provides low-risk electricity. In Asia, the coal sector is a driving force for economic growth and employment.
How are chemical transformations represented?
Chemical reactions are represented by means of chemical equations, which include the chemical formulas of the reacting substances and those of the substances produced, and a chemical equation must be balanced.
What is a molecule?
molecule, dim. of lat. moles “mole”]. – Chemical combination of two or more atoms, equal to each other (in the elements) or different (in the compounds), which can exist in the free state, and which represents the smallest quantity of matter that possesses the characteristic properties of the substance in question.
What cannot happen as a result of a chemical transformation *?
In chemical transformations, matter is never destroyed or created and the sum of the masses of the reactants is equal to the sum of the masses of the reaction products. In fact, chemical reactions take place according to Lavoisier’s Law which is the first and fundamental law of chemistry.
Visit Digital Global Times for more useful and informative answers!