Question

multiple-choice question

which is a single replacement reaction?

\\(2\text{ c}_5\text{h}_5 + \text{fe} = \text{fe}(\text{c}_5\text{h}_5)_2\\)

\\(\text{pb} + \text{feso}_4 = \text{pbso}_4 + \text{fe}\\)

\\(2\text{ mgi} + \text{mn}(\text{so}_3)_2 = 2\text{ mgso}_3 + \text{mni}_2\\)

Explanation:

Identify the definition of a single replacement reaction

A single replacement reaction has the general form:

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

where a free element replaces another element in a compound.

Analyze the given chemical equations

• First option: \(2\text{C}_5\text{H}_5 + \text{Fe}

ightarrow \text{Fe}(\text{C}_5\text{H}_5)_2\)
This is a synthesis (combination) reaction where two reactants combine to form a single product.

• Second option: \(\text{Pb} + \text{FeSO}_4

ightarrow \text{PbSO}_4 + \text{Fe}\)
The free element lead (\(\text{Pb}\)) replaces iron (\(\text{Fe}\)) in the compound iron(II) sulfate (\(\text{FeSO}_4\)), producing lead(II) sulfate (\(\text{PbSO}_4\)) and free iron (\(\text{Fe}\)). This fits the \(\text{A} + \text{BC}
ightarrow \text{AC} + \text{B}\) pattern.

• Third option: \(2\text{MgI} + \text{Mn}(\text{SO}_3)_2

ightarrow 2\text{MgSO}_3 + \text{MnI}_4\)
This is a double replacement reaction where two ionic compounds exchange ions.

Select the correct option

The second option represents a single replacement reaction.

Answer:

• (A) \(2\text{C}_5\text{H}_5 + \text{Fe}

ightarrow \text{Fe}(\text{C}_5\text{H}_5)_2\)

• **(B) \(\text{Pb} + \text{FeSO}_4

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

• (C) \(2\text{MgI} + \text{Mn}(\text{SO}_3)_2

ightarrow 2\text{MgSO}_3 + \text{MnI}_4\)