Chemical Reactions
Types of Chemical reactions
Lots of reactions take place around us in everyday life. Reactions are quit important in chemistry and in science generally. Chemical reaction is the changing of substances to other substances by the breaking of bonds in reactants and the formation of new bonds in products.
There are different types of chemical reaction:
1. Combination reaction
2. Decomposition reaction
3. Single-replacement reaction
4. Double-replacement reaction
5. Combustion reaction
Combination reaction is a chemical change in which two or more substances to form a new single substance. The reactants of most common combination reactions are either two elements or two compounds. The product a combination reaction is always a compound.
Decomposition reaction is a chemical change in which one substance is broken down into two or more products. These products can be any combination of elements and compounds. It is usually very difficult to predict the products of decomposition reactions.
Single-replacement reaction is a chemical change in which the atoms of less active element are replaced with atoms of elements which are more active. Usually the reactants are substance and element. Whenever one metal will replace another metal from a compound can be determined by the relative activities of the two metals. For predicting the products of this type of reaction we have the metal activity table, which is expressed above.
Li
K
Ca
Na
Mg
Al
Zn
Fe
Pb
H
Cu
Hg
Ag
The arrow shows the decreasing activity of metals and the metal that has the least activity (silver) doesn’t react at all with the elements which are in upper position in the table.
Double-replacement reaction is a chemical change that involves an exchange of possible ions between two compounds. Such reactions usually take pace between two ionic compounds in aqueous solutions and are often characterized the by production of precipitate.
Combustion reaction is a chemical change in which oxygen reacts with another substance, often producing energy in the form of heat and light.
The main and final thing I can add to my essay is that the reactions are very important for chemist. I think that the reactions for chemist are like ABC for the first grader. So I think we must learn it carefully…