Question

Question #19e8d

Answer 1

The limiting reactant in esterification is usually the cheapest reactant. However, you must confirm by calculating and comparing the amount of product each reactant will produce.

Consider the esterification reaction in which 18.5 g of 1-butanol are reacted with 19.0 g of acetic acid. What is the limiting reactant?

Step 1: Write the balanced chemical equation for the reaction.

C₄H₉OH + CH₃COOH → CH₃COOC₄H₉ + H₂O

Step 2: Convert all masses into moles.

18.5 g C₄H₉OH × `(1 mol C₄H₉OH)/(74.12 g C₄H₉OH)` = 0.250 mol C₄H₉OH

19.0 g CH₃COOH × `(1 mol CH₃COOH)/(60.05 g CH₃COOH)` = 0.316 mol CH₃COOH

Step 3: Calculate the mass of product from each reactant.

From 1-butanol:

0.250 mol C₄H₉OH ×

`(1 mol CH₃COOC₄H₉)/(1 mol C₄H₉OH) × (116.2 g CH₃COOC₄H₉)/(1 mol CH₃COOC₄H₉)` =

29.0 g CH₃COOC₄H₉

From acetic acid:

0.316 mol CH₃COOH ×

`(1 mol CH₃COOC₄H₉)/(1 mol CH₃COOH) × (116.2 g CH₃COOC₄H₉)/(1 mol CH₃COOC₄H₉)` =

36.8 g CH₃COOC₄H₉

Since 1-butanol gives the smaller amount of product, it is the limiting reactant.