Question

Write a short note on different type of chemical reaction

Answer 1

Answer:

Combination Reactions

A combination reaction, also known as a synthesis reaction, is a reaction in which two or more substances combine to form a single new substance. Combination reactions can also be called synthesis reactions .The general form of a combination reaction is:

A+B→AB(5.3.1)(5.3.1)A+B→AB

One combination reaction is two elements combining to form a compound. Solid sodium metal reacts with chlorine gas to product solid sodium chloride.

2Na(s)+Cl2(g)→2NaCl(s)(5.3.2)(5.3.2)2Na(s)+Cl2(g)→2NaCl(s)

Notice that in order to write and balance the equation correctly, it is important to remember the seven elements that exist in nature as diatomic molecules (H2H2, N2N2, O2O2, F2F2, Cl2Cl2, Br2Br2, and I2I2).

One sort of combination reaction that occurs frequently is the reaction of an element with oxygen to form an oxide. Metals and nonmetals both react readily with oxygen under most conditions. Magnesium reacts rapidly and dramatically when ignited, combining with oxygen from the air to produce a fine powder of magnesium oxide.

2Mg(s)+O2(g)→2MgO(s)(5.3.3)(5.3.3)2Mg(s)+O2(g)→2MgO(s)

Decomposition Reactions

A decomposition reaction is a reaction in which a compound breaks down into two or more simpler substances. The general form of a decomposition reaction is:

AB→A+B(5.3.4)(5.3.4)AB→A+B

Most decomposition reactions require an input of energy in the form of heat, light, or electricity.

Binary compounds are compounds composed of just two elements. The simplest kind of decomposition reaction is when a binary compound decomposes into its elements. Mercury (II) oxide, a red solid, decomposes when heated to produce mercury and oxygen gas.

2HgO(s)→2Hg(l)+O2(g)(5.3.5)(5.3.5)2HgO(s)→2Hg(l)+O2(g)

A reaction is also considered to be a decomposition reaction even when one or more of the products is still a compound. A metal carbonate decomposes into a metal oxide and carbon dioxide gas. For example, calcium carbonate decomposes into calcium oxide and carbon dioxide.

Answer 2

Answer:

Different types of chemical reaction are:

(a) Combination reactions: The reaction in which two or more than two substance combine together to form a single compound.

e.g. 2Mg+O

2

→2MgO

(b) Decomposition reaction: The reaction in which a compound decomposes to form two or more substance is called decomposition reaction.

e.g. CaCO

3

Δ

CaO+CO

2

(c) Displacement reaction: The reaction in which more reactive metal displaces the less reactive metal is called displacement reaction.

e.g. Fe+CuSO

4

→FeSO

4

+Cu

(d) Double displacement reaction: The reaction in which two different atoms or groups of (substance) atoms exchange for each other is called double displacement reaction.

e.g. Na

2

SO

4

(aq)+BaCl

2

(aq)→BaSO

4

(s)+2NaCl(aq)

(e) Oxidation reduction reaction: The reaction in which oxygen is added/ hydrogen is removed is called oxidation reaction.