Which is general chemical equation for an endothermic double-replacement reaction?

In a double-replacement reaction, two compounds exchange ions to form two new compounds. For an endothermic process, the general chemical equation can be represented as:

[ \text{AB} + \text{CD} \rightarrow \text{AD} + \text{CB} + \text{heat} ]

Here, compounds AB and CD react to form new compounds AD and CB, absorbing heat from the surroundings in the process.