Presentation on theme: "Five Types of Chemical Reactions Remember…a chemical reaction is when one compound is changed into a totally different compound. While there are millions."— Presentation transcript:
Five Types of Chemical Reactions Remember…a chemical reaction is when one compound is changed into a totally different compound. While there are millions of different types of reactions, they can all be classified into five general types.
Five Types of Chemical Reactions The five types are: 1.Synthesis 2.Decomposition 3.Single Replacement 4.Double replacement 5.Combustion
Synthesis Reaction A synthesis reaction takes place when two or more chemicals react to produce a single chemical. The reactants can be either elements or molecules (the product is always a molecule). A + B AB
Synthesis Reaction Practical use – the synthesis of nylon A key ingredient in toothbrushes, tents, carpet, clothes, guitar strings…
Decomposition Reaction A decomposition reaction takes place when a molecule breaks down into two or more substances. The reactant is always a molecule (never a single element). AB A + B
Decomposition Reaction An actual example: H 2 CO 3 → H 2 O + CO 2
Decomposition Reaction Practical use – car airbags The rapid decomposition of sodium azide causes the bag to inflate with nitrogen gas in about 0.04 seconds!
Single Replacement Reaction A single replacement reaction takes place when one element takes the place of another element in a molecule. The reactant side always consists of an element and a molecule. A +BC B + AC
Single Replacement Reaction An actual example: 2Na + 2H 2 O → 2NaOH + H 2
Double Replacement Reaction A double replacement takes place when two molecules exchange elements. There are at least two molecules on both sides of the arrow. AB + CD AD + BC
Double Replacement REaction An actual example: CaCO 3 + 2HCl → CaCl 2 + H 2 CO 3
Combustion Reaction A combustion reaction takes place when a hydrocarbon reacts rapidly with oxygen gas. A hydrocarbon is a molecule made of carbon and hydrogen atoms. The products are CO 2 and H 2 O. CH + O 2 CO 2 + H 2 O
Combustion Reaction An actual example: CH 4 + 2O 2 → CO 2 + 2H 2 O
Combustion Reaction Practical use – internal combustion engine Most forms of transportation use this type of engine.