Which of the following statements is not true about double replacement reactions? a. product may precipitate from solution b. product may be a gas c. product may be a molecular compound d. reactant may be a solid metal

The correct option is D.
In a double replacement reaction, one of the reactant can not be a solid metal, this is because, double replacement reaction takes place between two compounds which possess ions. During the reaction, the positive and the negative ions of the reactants will switch places, thus forming new compounds. This means that, each of the reactant must have a charge and a solid metal can not have a charge.

The third choice .. (: