1. What is a replacement reaction?

A replacement reaction or displacement reaction also known as exchange reaction is a reaction in which a higher reactive element displaces the lower reactive element from the compound. Single Replacement reactions are of three types- metal replacement, halogen replacement and hydrogen replacement. Examples: 2Ag+H 2 S→Ag 2 S+H 2 (Hydrogen replacement)

2. Why does displacement reaction happen?

When one element in a compound is replaced by another, it is called a single displacement reaction. A metal can only replace another metal, and a nonmetal can only replace another nonmetal.

3: Acid-base reaction is an example of double displacement reaction?

In double substitution reactions, two ionic compounds exchange anions or cations. When the reactants are acid and base, neutralisation reactions occur, and neutralisation reactions are generally favourable as long as the reaction demands a solid acid and/or base.

4. What is metal replacement?

Metal replacement reaction is a reaction in which a metal is displaced from another metal, which is more reactive than it. Example: Mg+Cu(NO 3 ) 2 →Mg(NO 3 ) 2 +Cu Magnesium is a metal with a higher reactivity than copper. When a strip of magnesium metal is immersed in aqueous copper (II) nitrate solution, it replaces the copper. The process produces aqueous magnesium nitrate and solid copper metal as byproducts.

5. What is halogen replacement?

Because the halogens gain electrons and the halide ions lose electrons, halogen displacement reactions are redox reactions. We can see which element is being oxidised and which is being reduced when we study one of the displacement reactions. Example: Br 2 +2KI→I 2 +2KBr Bromine has gained electrons, indicating that it has been reduced. The iodide ions have been oxidised because they have lost electrons.

Displacement Reactions - Definition, Types, Applications, FAQs

Chemistry
Some basic concepts of Chemistry
Displacement Reactions - Definition, Types, Applications, FAQs

Displacement Reactions - Definition, Types, Applications, FAQs

Team Careers360Updated on 02 Jul 2025, 04:30 PM IST

Define Displacement Reaction and give an example of double displacement reaction.

Displacement Reaction Definition: Displacement Reactions are extremely important chemistry processes. They are employed in a variety of fields in a variety of ways. For example, we employ electroplating, which is based on displacement reaction, to keep iron objects from rusting. The term "displacement reaction" refers to a reaction in which a portion of one reactant is displaced by another reactant. It's also known as a substitution reaction. As a result of the replacement of one reactant ion by another reactant ion.

Example: 2K+MgCl₂->2KCl+Mg

This example shows the displacement of magnesium from magnesium chloride by potassium which is more reactive than magnesium.

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Types of displacement reaction:

Define Single displacement reaction. Give single displacement reaction examples.

Single displacement reactions are those in which one element replace another element from its compound. Single replacement reactions are another name for this type of reaction.

A+B-C→A-C+B

Example: Zn+CuSO₄->ZnSO₄+Cu

This is a single displacement reaction in which zinc is more reactive than copper, thus zinc displaces the copper from copper sulfate and forms zinc sulfate and copper.

Define Double displacement reaction.

Double displacement reaction definition: Double displacement reaction are those in which two chemicals react by exchanging ions to produce two new molecules. Positive ions exchange negative ion partners in double replacement processes. Ionic chemicals dissolved in water undergo a lot of double displacement processes. The general equation represents a twofold replacement reaction.

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AB+CD→AC+BD

Atoms from two distinct compounds swap positions in a double displacement process. Two chemicals serve as reactants, while two compounds serve as products. Consider the following scenario: Fe₂O₃+6HCl→2FeCl₃+3H₂O

There are two types of Displacement reaction:

Neutralisation Reaction: The acid-base process produces salt (which is naturally neutral) and water. For example, sodium chloride and water are generated when an aqueous solution of hydrochloric acid is mixed with an aqueous solution of sodium hydroxide.

NaCl+H₂O →NaOH+HCl

Precipitation reaction: The precipitate is generated in a solution during chemical reaction in this reaction. When silver nitrate and sodium chloride are mixed in water, a white curdy silver chloride precipitate is created.

AgNO₃+NaCl →AgCl₂+NaNO₃

Applications of Displacement Reaction:

Welding with thermite: The reaction of aluminium and ferrous oxide to produce molten iron, which is used to weld rail rails.

2Al+Fe₂O₃ → Al₂O₃+2Fe

Aluminum is placed above the iron in the reactive series, thus aluminum is more reactive than iron which displaces iron from iron oxide to form aluminum oxide and iron.

Also red :

Blast furnace: The iron is removed from its ore Fe₂O₃, which is used to make steel, in a blast furnace. Carbon replaces Ferrous in the process, resulting in carbon dioxide. The reaction is: 3C+2Fe₂O₃→ 3CO₂+4Fe

Carbon displaces the iron from the iron oxide forming carbon dioxide and iron.

Metal extraction: Metals are formed by heating metal combinations in the presence of carbon. When a Cr₂O₃ combination is heated, chromium is produced. The reaction will be:

3C+2Cr₂O₃→3CO₂+4Cr

Carbon dioxide is produced by displacing chromium oxide by carbon.

Indigestion of acids: When we have an acidity problem, we should take sodium hydrogen carbonate, which removes hydrogen from the acid HCl. The reactions is:

NaHCO₃+HCl → H₂CO₃+NaCl.

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