Question

3
identify the reaction type: * (0.5 points)
what type of chemical reaction is this one?
ca + mgcl₂ --> cacl₂ + mg
single replacement
synthesis
decomposition
combustion
double replacement

Explanation:

To identify the reaction type, we analyze the given reaction \( \text{Ca} + \text{MgCl}_2
ightarrow \text{CaCl}_2 + \text{Mg} \). In a single - replacement reaction, one element replaces another element in a compound. Here, calcium (Ca) is a metal that replaces magnesium (Mg) in the compound \( \text{MgCl}_2 \) to form \( \text{CaCl}_2 \) and free magnesium (Mg).

• A synthesis reaction involves combining substances to form a more complex substance (e.g., \( A + B

ightarrow AB \)), which is not the case here.

• A decomposition reaction is the breakdown of a compound into simpler substances (e.g., \( AB

ightarrow A + B \)), which does not match this reaction.

• A combustion reaction usually involves a substance reacting with oxygen, often producing carbon dioxide and water, and this reaction has no oxygen involved.
• A double - replacement reaction involves the exchange of ions between two compounds (e.g., \( AB+CD

ightarrow AD + CB \)), but in our reaction, it is one element replacing another in a compound, not an exchange of ions between two compounds.

So, the reaction is a single - replacement reaction.

Answer:

A. Single replacement