Question 4

A gas, solid precipitate, or compound forms in the exchange of ions.

In a double replacement reaction, the primary outcome is the formation of a gas, solid precipitate, or a new compound as the ions of the reactants exchange partners. This exchange is a key characteristic of such reactions.

A) Energy in the form of heat or light is not always produced.

This option is incorrect as it does not accurately describe a defining feature of double replacement reactions. While it is true that energy may not always be produced, this statement does not specifically relate to the core processes of double replacement reactions.

B) The reactants can involve a variety of elements.

This statement is somewhat accurate but does not capture the essence of double replacement reactions. Although the reactants can indeed involve a variety of elements, this characteristic is too broad and does not specifically indicate the unique results of the reaction.

C) A gas, solid precipitate, or compound forms in the exchange of ions.

This option correctly identifies the fundamental outcome of double replacement reactions. The formation of a gas, solid precipitate, or new compound arises directly from the exchange of ions between the reacting compounds, which is the hallmark of this type of reaction.

D) All of the above.

This option is misleading because while it includes the correct aspects of double replacement reactions, it also includes incorrect statements. Since options A and B do not accurately reflect the defining features of double replacement reactions, this choice cannot be considered correct.

Conclusion

Option C is definitively correct as it specifically describes the outcome of double replacement reactions, emphasizing the formation of a gas, solid precipitate, or compound through the exchange of ions. The other options either misrepresent characteristics of double replacement reactions or fail to encapsulate their essence, making them incorrect in this context.