What is the difference between displacement and double displacement reactions? Write equations for these reactions.

Displacement and double displacement reactions are both types of chemical reactions, but they involve different processes and result in different products.

Displacement Reaction: In a displacement reaction, one element displaces another element in a compound, leading to the formation of a new compound and a free element. These reactions typically involve a more reactive element displacing a less reactive one from its compound.

Example equation:
\text{Zn(s) + 2HCl(aq) -> ZnCl_2(aq) + H_2(g)}

In this reaction, zinc (Zn) displaces hydrogen (H) from hydrochloric acid (HCl) to form zinc chloride (ZnCl2) and hydrogen gas (H2).

Double Displacement Reaction: In a double displacement reaction, the positive and negative ions of two compounds switch places to form two new compounds. This reaction usually occurs in aqueous solutions and can result in the formation of a precipitate, gas, or water.

Example equation:
\text{NaCl(aq) + AgNO_3(aq) -> NaNO_3(aq) + AgCl(s)}

In this reaction, sodium chloride (NaCl) reacts with silver nitrate (AgNO3) to form sodium nitrate (NaNO3) and silver chloride (AgCl), which precipitates out of the solution.

These reactions demonstrate the fundamental differences between displacement and double displacement reactions in terms of the rearrangement of atoms and ions.