Ferrocene, Fe(C₅H₅)₂(s), can be prepared by reacting 3.0 g of FeCl₂(s) with an equal mass of cyclopentadiene, C₅H₆(l), and an excess of KOH, as shown in the following reaction FeCl₂ + 2C₅H₆ + 2KOH $\rarr$ FeC₁₀H₁₀ + 2H₂O A student who carried out this reaction obtained 2.7 g of ferrocene. Of the following choices which has three correct answers?

Question

Quizplus · Accepted Answer

In order to determine the limiting reagent and the theoretical yield, we need to calculate the moles of each reactant using their respective molar masses.

FeCl2: 2(35.5 g/mol) + 55.9 g/mol = 127 g/mol = 0.0236 mol
Cyclopentadiene: 5(12.01 g/mol) + 5(1.01 g/mol) = 70.14 g/mol = 0.0404 mol

Since the reaction consumes 2 moles of cyclopentadiene for every 1 mole of FeCl2, the cyclopentadiene is the limiting reagent. Therefore, we can calculate the theoretical yield based on the amount of cyclopentadiene used in the reaction:

0.0404 mol  ferrocene/mol cyclopentadiene * 186.04 g/mol ferrocene = 7.53 g

The actual yield obtained by the student is 2.7 g, so the percentage yield is:

2.7 g ferrocene/7.53 g ferrocene * 100% = 35.8%

The only choice that has three correct responses is D, as it correctly identifies cyclopentadiene as the limiting reagent, provides a theoretical yield of 4.2 g (which is close to the actual yield of 2.7 g), and gives a percentage yield of 64%.

Ferrocene, Fe(C5H5)2(s), Can Be Prepared by Reacting 3 →\rarr→ FeC10H10 + 2H2O a Student Who Carried Out This Reaction

Ferrocene, Fe(C₅H₅)₂(s), Can Be Prepared by Reacting 3 $\rarr$ FeC₁₀H₁₀ + 2H₂O
a Student Who Carried Out This Reaction