Final answer:
The equation Mg(OH)2 + 2HNO3 → Mg(NO3)2 + 2H2O represents a double replacement reaction.
Step-by-step explanation:
The type of reaction represented by the equation Mg(OH)2 + 2HNO3 → Mg(NO3)2 + 2H2O is a double replacement reaction. In a double replacement reaction, the positive ions of two ionic compounds switch places to form two new compounds. In this reaction, the magnesium ions (Mg²⁺) from Mg(OH)2 switch places with the nitrate ions (NO3⁻) from HNO3 to form Mg(NO3)2 and 2H2O as the products.