Question

Which of the following reactions represents a double displacement reaction?

• A. $2Pb\left(N{O}_3{)}_2\right(s)\to 2PbO(s)+4N{O}_2(g)+O_2(g)$
• B. $BaC{l}_2\left(aq\right)+N{a}_{2}S{O}_4\left(aq\right)\to BaS{O}_4\left(s\right)+2NaC{l}_{(}aq)$
• C. $Zn\left(s\right)+2AgN{O}_3\left(aq\right)\to Zn\left(N{O}_3{)}_2\right(aq)+2Ag(s)$
• D. $2FeS{O}_4\left(s\right)\to F{e}_2{O}_3\left(s\right)+S{O}_2\left(g\right)+S{O}_3\left(g\right)$

Answer 1

The correct option is B $BaC{l}_2\left(aq\right)+N{a}_{2}S{O}_4\left(aq\right)\to BaS{O}_4\left(s\right)+2NaC{l}_{(}aq)$

Double displacement reactions are the reactions in which an exchange of ions between the reactants takes place. The given reaction is an example of a double displacement reaction in which an exchange of ions takes place between the two reactants (Na₂SO₄ and BaCl₂). Here, barium chloride reacts with sodium sulphate to produce barium sulphate and sodium chloride.