Question

\[Zn\left( s \right)CuS{O_4}\left( {aq} \right) \to ZnS{O_4}\left( {aq} \right) + Cu\left( s \right)\] What type of chemical reaction is shown in the above equation?
A. Combination reaction.
B. Dissociation reaction.
C. Displacement reaction.
D.Double displacement reaction.

Answer 1

Hint: A chemical reaction is a process in which reactants are converted into products by either bond-breaking or bond-making. There are five basic types of reactions: synthesis, decomposition, combustion, neutralization, and displacement reactions.

Complete step by step answer:
In a chemical reaction, when two or more reactants combine to form a single product or compound, we call it a combination reaction. In such a reaction, we are synthesizing a compound by the reaction of two or more reactants, therefore it is a synthesis reaction too.
 \[A + B \to AB\]
These reactions involve the formation of new bonds and the release of large amounts of energy in the form of heat. Therefore, most of the combination reactions are exothermic in nature.
When coal burns in air, it produces carbon dioxide gas and the reaction is called combustion reaction.
 \[C(s) + {O_2}(g) \to C{O_2}(g)\]
When an atom or a set of an atom is displaced in a molecule by another atom is called displacement reaction, the reaction, in general, is shown below.
 \[A + B - C \to A - C + B\]
When two compounds react and their one atom or group of atoms gets exchanged to generate another two compounds, the reaction will be known as double displacement reaction. The general equation of this reaction is shown below.
 \[A - D + B - C \to A - C + B - D\]
In the case of dissociation reaction, the large molecules get dissociated into small molecules. And the energy decreases. the general form is,
 \[A - D \to A + D\]
Now according to these definitions of different types of reactions, the given reaction is a displacement reaction. Because in this reaction the sulfate ion is displaced from copper to zinc.
 \[Zn\left( s \right)CuS{O_4}\left( {aq} \right) \to ZnS{O_4}\left( {aq} \right) + Cu\left( s \right)\]

So, the correct answer is C.

Note:
When oxygen and hydrogen react to form water, they combine and produce a new compound. So, it is a combination reaction.
 \[{H_2} + {O_2} \to 2{H_2}O\] .But when water freezes on cooling becomes ice and this is not a chemical reaction, it is a mere physical change. Ice melts on heating are also the same i.e. phase change from solid to liquid. No chemical change takes place in both.
 \[{H_2}O(s) \rightleftharpoons {H_2}O(l)\]