Question

Which example shows a double replacement reaction?

A. Cu + Ag(NO3)2 → Ag + Cu(NO3)2
B. KCl + AgNO3 → AgCl + KNO3
C. Na2CO3 → Na2O + CO2
D. CaO + CO2 + CaCO3

Answer 1

The example that shows a double replacement reaction is B. KCl + AgNO3 → AgCl + KNO3, where potassium and silver trade places, forming AgCl as a precipitate and KNO3 in solution.

Step-by-step explanation:

The example that shows a double replacement reaction is:

B. KCl + AgNO3 → AgCl + KNO3

In this reaction, the potassium (K) cation swaps places with the silver (Ag) cation, conforming to the pattern of a classic double displacement reaction. We find that the chloride (Cl-) anion pairs up with silver (Ag+) to form silver chloride (AgCl), a precipitate, while the nitrate (NO3-) anion pairs with potassium (K+) to form potassium nitrate (KNO3), which remains in solution. This type of reaction typically occurs when one of the products is insoluble and drops out of the solution as a solid precipitate, driving the reaction forward.