How to identify Double replacement

The easiest way to identify a double displacement reaction is to check to see whether or not the cations exchanged anions with each other.

Explanation:

if the states of matter are cited, is to look for aqueous reactants and the formation of one solid product (since the reaction typically generates a precipitate).

a:

by the combination of an unlimited number of elements

o conteúdo de calor de um sistema é igual à entalpia apenas para um sistema que é constante