Question

(a) what is the difference between displacement and double displacement reactions ? Write equations for these reactions.

(b) What do you mean by a precipition reaction ? Explain giving and example.

Answer 1

(a)

In displacement reactions, a more reactive metal displaces a less reactive metal from its solution while in double displacement reactions, two reactants in solution exchange their ions. For example,

(i) $Fe\left(s\right)+CuS{O}_4\left(aq\right)⟶FeS{O}_4\left(aq\right)+Cu\left(s\right)$

This is a displacement reaction where iron displaces copper from its solution.

(ii) $AgN{O}_3\left(aq\right)+NaCl\left(aq\right)⟶AgCl\left(s\right)+NaN{O}_3$

This is a double displacement reaction where silver nitrate and sodium chloride exchange $C{l}^{-}$ and $N{O}_3^{-}$ ions between them.

(b)

Any reaction that produces a precipitate can be called a precipitation reaction.
Precipitation reactions produce insoluble salts which settle down as precipitate.

A precipitate is a solid product which separates out from a solution during a chemical reaction.

Precipitate is insoluble substance.

for ex:-$\underset{\text{Potassium iodide}}{KI}+PbN{O}_3⟶KN{O}_3+\underset{\text{yellow precipitate}}{PbI}$

Here in this reaction lead iodide is formed as a precipitate.