Which equation represents a single replacement reaction?

Which equation represents a single replacement reaction?

• A. AB + C --> AC + B
• B. AB + CD --> AD + CB
• C. AB --> A + B
• D. A + B --> AB

Answer: (A)

Single replacement (single displacement) reactions involve one element taking the place of another element in a compound, yielding a new compound and a free element. In AB + C → AC + B, the single element C replaces B in the compound AB, forming AC and freeing B. This illustrates the defining pattern of a single replacement. For contrast, the other forms represent different types of reactions. AB + CD → AD + CB is a double displacement, where partners in two compounds swap. AB → A + B is a decomposition, where a compound breaks into simpler substances. A + B → AB is a synthesis, where two substances combine to form a single compound.

Single replacement (single displacement) reactions involve one element taking the place of another element in a compound, yielding a new compound and a free element. In AB + C → AC + B, the single element C replaces B in the compound AB, forming AC and freeing B. This illustrates the defining pattern of a single replacement.

For contrast, the other forms represent different types of reactions. AB + CD → AD + CB is a double displacement, where partners in two compounds swap. AB → A + B is a decomposition, where a compound breaks into simpler substances. A + B → AB is a synthesis, where two substances combine to form a single compound.