Question

What happens during a double-replacement reaction?

Answer 1

A double displacement reaction is a type of reaction where a part of one reactant is replaced by part of another reactant twice in a reaction.

The general form is AB + CD --> AD + CB
An example:
\[Pb(NO_{3})_{2} + 2 KI \rightarrow PbI_{2} + 2 KNO_{3}\]
you see the NO3 part (nitrate) was first with lead and after the reaction with potassium and the iodide goes from potassium to lead after the reaction.

Answer 2

Two couples change dates at the dance. It's as simple as that.