Question

What is an example of a double displacement reaction?

Answer 1

Double displacement reactions commonly involve ionic compounds; each cation starts out combined with one anion and ends up combined with the other reactant's anion. Examples given in the explanation.

Explanation:

In water solvent (precipitation of silver chloride):

`color(red)("Ag")color(blue)("NO"_3)+color(orange)("K")color(purple)("Cl")->color(red)("Ag")color(purple)("Cl")(s)+color(orange)("K")color(blue)("NO"_3)`

In water solvent (one method for production of sodium hydroxide):

`color(red)("Na")_2color(blue)("CO"_3)+color(orange)("Ca")color(purple)("(OH)")_2->2color(red)("Na")color(purple)("OH")+color(orange)("Ca")color(blue)("CO"_3)(s)`

In liquid ammonia solvent (precipitation of potassium chloride) -- note the differeent solubility relationships in ammonia versus water which make the first example go in reverse:

`color(red)("K")color(blue)("NO"_3)+color(orange)("Ag")color(purple)("Cl")->color(red)("K")color(purple)("Cl")(s)+color(orange)("Ag")color(blue)("NO"_3)`