Problem 70 - Chemistry The Central Science

Question

(a) What is the empirical formula of starch? (b) What is the monomer that forms the basis of the starch polymer? (c) What bond connects the monomer units in starch: amide, acid, ether, ester, or alcohol?

Step-by-Step Solution

Answer

(a) The empirical formula of starch is \(C_6(H_2O)_6\). (b) The monomer that forms the basis of the starch polymer is glucose, with the molecular formula \(C_6H_{12}O_6\). (c) The bond connecting the monomer units in starch is an ether bond.

Step 1: (a) Empirical Formula of Starch

Starch is a carbohydrate and its empirical formula can be represented as \(C_n(H_2O)_n\), where "n" is a positive integer. Starch is a polymer made of many repeating glucose units. The monomer unit glucose has the molecular formula \(C_6H_{12}O_6\), and therefore, the empirical formula of starch can be represented as \(C_6(H_2O)_6\).

Step 2: (b) Monomer of Starch

Starch is a polymer made of many glucose molecules connected through glycosidic bonds. So, the monomer that forms the basis of the starch polymer is the glucose molecule, with the molecular formula \(C_6H_{12}O_6\).

Step 3: (c) Bond Connecting Monomer Units in Starch

When glucose molecules join together to form starch, they do so through a process called condensation reaction. During this reaction, an oxygen atom from one glucose molecule reacts with a hydroxyl group (-OH) from another glucose molecule, resulting in the formation of a glycosidic bond and a water molecule as a side product. The glycosidic bond is an ether bond, so the bond connecting the monomer units in starch is an ether bond.