Question

Select the correct answer from the choices A, B, C, and D which are given. Write only the letter corresponding to the correct answer.

Which is the correct general form for single displacement reaction?

• A. $\mathrm{AB}+\mathrm{C}\to \mathrm{A}+\mathrm{CB}$
• B. $\mathrm{A}+\mathrm{B}\to \mathrm{AB}$
• C. $\mathrm{AB}+\mathrm{CD}\to \mathrm{AD}+\mathrm{CB}$
• D. None of the above

Answer 1

The correct option is A

$\mathrm{AB}+\mathrm{C}\to \mathrm{A}+\mathrm{CB}$

The explanation for the correct option:

(A) -$\mathrm{AB}+\mathrm{C}\to \mathrm{A}+\mathrm{CB}$

Simple displacement reaction:

• A displacement reaction is also called a substitution reaction.
• These are the reactions involving the displacement of an element from a compound by another element that takes its place.
• The ability of an element to displace another is determined by its relative position in an electrochemical series.

For example:

$$\begin{gathered} \mathrm{Zn}\left(\mathrm{s}\right)+{\mathrm{CuSO}}_4\left(\mathrm{aq}\right)\to {\mathrm{ZnSO}}_4\left(\mathrm{aq}\right)+\mathrm{Cu}\left(\mathrm{s}\right) \\ \mathrm{Zinc}\mathrm{Copper}\mathrm{sulphate}\mathrm{Zinc}\mathrm{sulphate}\mathrm{Copper} \end{gathered}$$

Therefore, option A is correct.

The explanation for the incorrect options:

(B) - $\mathrm{A}+\mathrm{B}\to \mathrm{AB}$

Synthesis or direct combination reaction:

• When the molecules of two or more substances combine to form molecules of a single substance, the reaction is called a combination reaction.
• A combination reaction is also called a synthesis reaction.

For example:

$$\begin{gathered} \mathrm{C}\left(\mathrm{s}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)\to {\mathrm{CO}}_2\left(\mathrm{g}\right) \\ \mathrm{Carbon}\mathrm{Oxygen}\mathrm{Carbon}\mathrm{dioxide} \end{gathered}$$

(C) - $\mathrm{AB}+\mathrm{CD}\to \mathrm{AD}+\mathrm{CB}$

Double decomposition reaction:

• These are the reactions in which two compounds exchange their radicals to form two different compounds.
• A double displacement reaction is a type of reaction in which two reactants exchange ions to form two new compounds.
• Most of the double displacement reactions occur between ionic compounds.

For example:

$$\begin{gathered} {\mathrm{AgNO}}_3\left(\mathrm{aq}\right)+\mathrm{NaCl}\left(\mathrm{aq}\right)\to \mathrm{AgCl}\left(\mathrm{s}\right)+{\mathrm{NaNO}}_3\left(\mathrm{aq}\right) \\ \mathrm{Silver}\mathrm{nitrate}\mathrm{Sodium}\mathrm{chloride}\mathrm{Silver}\mathrm{Chloride}\mathrm{Sodium}\mathrm{nitrate} \end{gathered}$$

Hence option(A) is the correct answer.