Chapter 17, Problem 17.21P

(a)

Interpretation Introduction

Interpretation:

Structural formula of a compound with the given formula upon oxidation by potassium dichromate in aqueous sulphuric acid gives carboxylic acid has to be drawn.

Concept-Introduction:

Oxidation:

Loss of electrons from an atom ion or molecule during a chemical reaction is known as oxidation.  Oxidation state of atom ion or molecule will increase in this process.  In simple it is the addition of oxygen.

Example:

Here ${\text{Fe}}^{\text{2+}}$ oxidized to ${\text{Fe}}^{\text{3+}}$ by the removal of a single electron.

Oxidation of alcohols:

Oxidation of alcohol gives aldehydes ketones carboxylic acid Primary alocohols on oxidation yield carboxylic acid.  Secondary alcohol on oxidation gives ketone.  Depending upon the reaction conditions primary alcohols can be oxidized to aldehyde or carboxylic acid.  In the formation of carboxylic acid the alcohol is first oxidized to aldehyde which is then oxidized to form carboxylic acid.  Oxidation is not possible in tertiary alcohol because there is no reactive $\text{C-H}$ bond present adjacent to the $\text{C-OH}$ group so oxidation cannot be done without breaking the bond.  Common oxidizing agents are dichromate, collins reagent, dimethyl sulfoxide, potassium permanganate etc.

(b)

Interpretation Introduction

Interpretation:

Structural formula of a compound with the given formula upon oxidation by potassium dichromate in aqueous sulphuric acid gives carboxylic acid has to be drawn.

Concept-Introduction:

Oxidation:

Loss of electrons or loss of hydrogen from an atom ion or molecule during a chemical reaction is known as oxidation.  Oxidation state of atom ion or molecule will increase in this process.  In simple it is the gain of oxygen.

Example:

Here ${\text{Cu}}_{\text{2}}$ oxidized to ${\text{Cu}}^{\text{2+}}$ by the removal of two electrons.

Oxidation of alcohols:

Oxidation of alcohol gives aldehydes ketones carboxylic acid Primary alcohols on oxidation yield carboxylic acid.  Secondary alcohol on oxidation gives ketone.  If mild oxidizing agents are used the the reaction will end with an aldehydic product.  In the formation of carboxylic acid the alcohol is first oxidized to aldehyde which is then oxidized to form carboxylic acid.  Oxidation is not possible in tertiary alcohol because there is no reactive $\text{C-H}$ bond present adjacent to the $\text{C-OH}$ group so oxidation cannot be done without breaking the bond.  Common oxidizing agents are potassium dichromate, collins reagent, dimethyl sulfoxide, potassium permanganate etc.

(c)

Interpretation Introduction

Interpretation:

Structural formula of a compound with the given formula upon oxidation by potassium dichromate in aqueous sulphuric acid gives carboxylic acid has to be drawn.

Concept-Introduction:

Oxidation:

Loss of electrons from an atom ion or molecule during a chemical reaction is known as oxidation.  Oxidation state of atom ion or molecule will increase in this process.  Oxidizing agent is getting reduced in oxidation.  In simple it is the addition of oxygen or removal of hydrogen.

Example:

Here ${\text{H}}_{{}_{\text{2}}}$ oxidized to ${\text{2H}}^{\text{+}}$ by the removal of two electron.

Oxidation of alcohols:

Oxidation of alcohol gives aldehydes ketones carboxylic acid Primary alcohols on oxidation yield carboxylic acid.  Secondary alcohol on oxidation gives ketone.  In the formation of carboxylic acid the alcohol is first oxidized to aldehyde which is then oxidized to form carboxylic acid.  Oxidation is not possible in tertiary alcohol because there is no reactive $\text{C-H}$ bond present adjacent to the $\text{C-OH}$ group so oxidation will not be possible without breaking the bond.  Common oxidizing agents are pyridinium chlorochromate, dichromate, collins reagent, dimethyl sulfoxide, potassium permanganate etc.