There are many types of chemical reactions, five general ones of which I will be describing. Chemical changes are a result of chemical reactions. All chemical reactions involve a change in substances and a change in energy. Neither matter nor energy is created or destroyed in a chemical reaction, only changed. There are so many chemical reactions that it is helpful to classify them into 5 general types, which include the following: synthesis, combustion, decomposition, single-replacement, and double-replacement. The reaction of synthesis includes two or more substances, which will then turn into one compound, usually being a more complex substance.
The formula for synthesis is A+B â†’ AB, and an example would be 2Na+Cl2 â†’ 2NaCl. Another good example to better understand is two simple substances, such as hydrogen and oxygen can yield a more complex substance â†’ water. Combustion has reactants of: metal and oxygen, nonmetal and oxygen, and a compound and oxygen yielding either the oxide of the metal, the oxide of the nonmetal, or two or more oxides. If there is not enough oxygen in a complete combustion, carbon monoxide is formed.
Most all combustion reactions are exothermic, meaning they give off heat. A good example of a reaction is CH4+2O2 â†’ CO2+ H2O. Also a good example to compare would be water (H2O) â†’ hydrogen and oxygen, which is just the opposite of synthesis, Decomposition is the opposite of synthesis. The decomposition process uses only one reactant, a compound, and will yield two or more elements/compounds. A compound is broken down into simpler substances, usually through electrolysis. The formula for decomposotion is AB â†’ A+B and an example would include 2H2O â†’ 2H2 + O2.
In a single-replacement reaction, there.