Are exothermic reactions decomposition reactions or are they synthesis reactions?
Synthesis reactions are generally characterized by being exothermic. Decomposition reactions are usually endothermic.
Synthesis and decomposition reactions are sometimes described as opposite reactions because a synthesis reaction is when there is a combination of two or more substances and a compound results, and a decomposition is when a compound is broken down into simpler substances, usually through electrolysis. An example of a synthesis reaction: A + B -----> AB An example of a decomposition reaction: AB -----> A + B
What about combustion reactions makes them different from either synthesis or decomposition reactions?
The short answer is combustion reactions are a subset of synthesis reactions that require one of the reactants to be oxygen. Common combustion of organic molecules results in the formation of CO2 . However, it is not required that combustion be limited to organic molecules. They are different from decomposition reactions in the same way synthesis is the opposite of decomposition.
The reactions in which two or more substances combine to produce a single substance are known as Combination or Synthesis Reaction. They may be represented by X + Y → XY Combination reactions are usually exothermic. Chemical decomposition, analysis or breakdown is the separation of a chemical compound into elements or simpler compounds. It is sometimes defined as the exact opposite of a chemical synthesis.The generalized reaction for chemical decomposition is: AB → A +…
They are opposite reactions. In a synthesis reaction, two or more simple substances combine to form a more complex substance, while in a decomposition reaction, a complex substance breaks down to form two or more simpler substances. An example of a synthesis reaction is Na + Cl --> NaCl. An example of a decomposition reaction is NaCl --> Na + Cl.
Endothermic reactions and Exothermic reaction are never the same. They are both different. Definitions Endothermic:- reactions that take in energy. For example:- electrolysis, thermal decomposition and the reaction between ethanic acid and sodium carbonate. Exothermic:- reactions that transfer energy to the surroundings. For example:- burning, neutralisation and the reaction between water and calcium oxide.
Exothermic reactions give out energy overall. Here are some exothermic reactions: - Combustion of fuels such as hydrogen & methane - Neutralisation of an acid by an alkali - Reaction between sulphur & iron Endothermic reactions take in energy overall. Here are some endothermic reactions: - Reactions involved in cooking - The thermal decomposition of calcium carbonate - Photosynthesis in which plants use sunlight, carbon dioxide & water to make their own food