Question

Given the following equation: Cu + 2AgNO3 Cu(NO3)2 + 2 Ag... If 4 moles of AgNO3 AND 4 moles of Cu react, which is the limiting reactant?

A. Cu
B. AgNO3
C. Cu(NO3)2
D. Ag

Answer 1

The limiting reactant when 4 moles of Cu and 4 moles of AgNO3 are reacted is AgNO3, because the reaction requires twice as much AgNO3 as Cu.

Step-by-step explanation:

To determine the limiting reactant in a chemical reaction, we compare the mole ratios of the reactants with the coefficients in the balanced chemical equation. The given reaction is:

Cu (s) + 2AgNO3(aq) → Cu(NO3)2 (aq) + 2 Ag (s)

According to the balanced equation, 1 mole of Cu reacts with 2 moles of AgNO3. If we have 4 moles of each reactant, the stoichiometry of the reaction tells us that we need 8 moles of AgNO3 to completely react with 4 moles of Cu. However, since only 4 moles of AgNO3 are available, it is the limiting reactant because we do not have enough AgNO3 to react with all of the Cu.

The correct answer is therefore B. AgNO3.