Exchange Reaction : Chemical Reaction

Definition

An exchange reaction (other names are displacement reaction and replacement reaction) is a chemical reaction in which an elemental species or an ionic component of one reactant compound exchanges places with another reactant.

Reaction Principles

During the mechanism of the reaction, one component of a reactant is displaced and replaced by another component from a second reactant. The result is an exchange of corresponding components between the reactants. In simple terms, the chemical components switch (swap) places with their counterpart reactant. The reactivity series (see table following) for metals (cations) and anions in aqueous solutions and the solubility table for compounds, directly correlate the reaction outcome with predictions.

Reactivity Series for Metals and Halogens
potassium K sodium Na calcium Ca magnesium Mg aluminium Al carbon C zinc Zn iron Fe tin Sn lead Pb hydrogen H copper Cu silver Ag gold Au	Most reactive ↑ ↓ Least reactive	F flourine Cl chlorine Br bromine I iodine
Although carbon C and hydrogen H are not metals, they are useful to include in the reactivity series for metals.

Usually, the exchange takes place in an aqueous medium involving ionic compounds. The reactions are of two types; single displacement reaction (also called a substitution reaction) and double displacement reaction (also called metathesis reaction or a double replacement reaction). These are represented by the following equations.

Single displacement reaction:

A + BX → AX + B

Double displacement reaction:

AX + BY → AY + BX

Full Definition

Published on: 24 Jan 2018 at 0110.
Last updated: 7 Jul 2018 at 1538.

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