1. Metal-Metal Replacement: This type involves a more reactive metal displacing a less reactive metal from its compound.
* Example: Zinc (Zn) reacting with copper(II) sulfate (CuSO₄) to form zinc sulfate (ZnSO₄) and copper (Cu).
Zn(s) + CuSO₄(aq) → ZnSO₄(aq) + Cu(s)
2. Metal-Hydrogen Replacement: This type involves a metal reacting with an acid to displace hydrogen gas (H₂).
* Example: Magnesium (Mg) reacting with hydrochloric acid (HCl) to form magnesium chloride (MgCl₂) and hydrogen gas.
Mg(s) + 2HCl(aq) → MgCl₂(aq) + H₂(g)
Important Notes:
* Activity Series: The reactivity of metals is determined by the activity series, which helps predict whether a single-replacement reaction will occur. A more reactive metal will replace a less reactive metal in a compound.
* Non-metal Replacement: While less common, non-metals can also participate in single-replacement reactions. For example, chlorine (Cl₂) can displace bromine (Br₂) from potassium bromide (KBr) to form potassium chloride (KCl) and bromine.
* Other Considerations: Factors such as concentration, temperature, and the presence of catalysts can influence the rate and extent of a single-replacement reaction.
