Q.21. Give two examples each of: (1) Double displacement
reactions (ii) Redox reactions (iii) Combination
reactions.
Answers
Answer:
1. Double displacement reaction
Double displacement reactions generally take place in aqueous solutions in which the ions precipitate and there is an exchange of ions. For example, on mixing a solution of barium chloride with sodium sulphate, a white precipitate of barium sulphate is immediately formed. These reactions are ionic in nature.
2. Single displacement reaction
A chemical reaction in which - an element or radical - has replaced another element in a compound.
Example - A + BC - - > AC + B
3. REDOX REACTION
A Chemical reaction involving - oxidation of one substance and reduction of the other is called a redox reaction. All chemical reactions involving loss or gain of electrons are considered as redox reaction. Where oxidation and reduction occurs simultaneously.
Example : Cl2 + H2S - - - > 2HCl + S
A double displacement reaction, also known as a double replacement reaction or metathesis reaction, is a type of reaction that occurs when the cations and anions switch between two reactants to form new products. ... After that, we switch the ions of the two reactants and write down the products.
A single-displacement reaction occurs when an element replaces another element in a compound. A metal only replaces a metal, and a nonmetal only replaces a nonmetal. Only a more reactive element can replace the other element in the compound with which it reacts
An oxidation-reduction (redox) reaction is a type of chemical reaction that involves a transfer of electrons between two species. ... The formation of hydrogen fluoride is an example of a redox reaction. We can break the reaction down to analyze the oxidation and reduction of reactants.
A decomposition reaction occurs when one reactant breaks down into two or more products. This can be represented by the general equation: AB → A + B. Examples of decomposition reactions include the breakdown of hydrogen peroxide to water and oxygen, and the breakdown of water to hydrogen and oxygen.
Na2 + H2O `->` 2NaOH. Here sodium oxide is combined with water gives sodium hydroxide.4Li + O2 `->` 2Li2O. Here lithium is combined with oxygen to form lithium oxide.2Mg + O2 `->` 2 MgO. ...H2 + Cl2 `->` 2 HCL. ...
NH3 + HCl `->` NH4Cl. ...
Explanation:
Answer:
Displacement reaction :
A single-displacement reaction, also known as a single-replacement reaction, is a reaction by which one
(or more) element(s) replaces an/other element(s) in a compound. It can be represented generally as:
A+B−C→A−C+B
All simple metal with acid reactions are single displacement reactions. For example, the reaction
between magnesium, Mg, and hydrochloric acid, HCl, forms magnesium chloride, MgCl
2
, and hydrogen,
H
2
.
Mg(s)+2HCl(aq)→MgCl
2
(aq)+H
2
(g)
Decomposition reaction :
A decomposition reaction is a type of chemical reaction where one reactant yields two or more
products.
The general form for a decomposition reaction is
AB→A+B
Water can be separated by electrolysis into hydrogen gas and oxygen gas through the decomposition
reaction: 2H
2
O→2H
2
+O
2
Another example is the spontaneous decomposition of hydrogen peroxide into water and oxygen: 2
H
2
O
2
→2H
2
O+O
2
The decomposition of potassium chlorate into potassium chloride and oxygen is yet another example:
2KClO
3
→2KCl+3O
2
Combination reaction :
A combination reaction (also known as a synthesis reaction) is a reaction where two or more elements
or compounds (reactants) combine to form a single compound (product). Such reactions may be
represented by equations of the following form : X+Y→XY.
Formation of calcium oxide by the combination elements calcium and oxygen.
2Ca+O
2
→2CaO
Formation of ammonia by the combination of elements nitrogen and hydrogen.
N
2
+3H
2
→2NH
3