Question

which of the following is a single replacement reaction?

• pb + feso4 -> pbso4 + fe
• p4 + 3 o2 -> 2 p2o3
• caco3 -> cao + co2

Explanation:

Identify the definition of a single replacement reaction

A single replacement reaction follows the general form:

$$ \text{A} + \text{BC} ightarrow \text{B} + \text{AC} $$

where a free element \(\text{A}\) replaces an element \(\text{B}\) in a compound \(\text{BC}\).

Analyze the given chemical equations

• Option 1: \(\text{Pb} + \text{FeSO}_4

ightarrow \text{PbSO}_4 + \text{Fe}\)
The free element lead (\(\text{Pb}\)) replaces iron (\(\text{Fe}\)) in the compound \(\text{FeSO}_4\), yielding free iron (\(\text{Fe}\)) and the compound lead sulfate (\(\text{PbSO}_4\)). This matches the single replacement pattern.

• Option 2: \(\text{P}_4 + 3\text{O}_2

ightarrow 2\text{P}_2\text{O}_3\)
Two reactants combine to form a single product, which is a synthesis reaction.

• Option 3: \(\text{CaCO}_3

ightarrow \text{CaO} + \text{CO}_2\)
A single reactant breaks down into multiple products, which is a decomposition reaction.

Select the correct option

The first option represents a single replacement reaction.

Answer:

• **(A) \(\text{Pb} + \text{FeSO}_4

ightarrow \text{PbSO}_4 + \text{Fe}\) (Correct answer)**

• (B) \(\text{P}_4 + 3\text{O}_2

ightarrow 2\text{P}_2\text{O}_3\)

• (C) \(\text{CaCO}_3

ightarrow \text{CaO} + \text{CO}_2\)