Chapter 4, Problem 4.66EP

(a)

Interpretation Introduction

Interpretation:

The compound that has higher solubility in water among the given pair has to be identified.

Concept Introduction:

Carbonyl groups are the one which contain a double bond between carbon and oxygen atom.  Aldehydes and ketones possess this carbonyl functional group in it.  The structural representation of a carbonyl group can be given as shown below,

Aldehydes contain a carbonyl group that contains a hydrogen atom and a carbon atom bonded to it.  Aldehyde that has one and two carbon atoms are gas at room temperature.  The physical state of aldehyde that contains three carbon atoms to eleven carbon atoms that are not branched is liquid at room temperature.  Aldehydes that contain more than eleven carbon atoms are solid at room temperature.

Ketones contain a carbonyl group that contains two carbon atoms bonded to it.  For a compound to be ketone, a minimum of three carbon atom is required.  Ketones that contain three carbon atoms to eight carbon atoms which have the carbonyl group at the second carbon atom are liquid at room temperature.

Solubility of aldehydes and ketones depend upon the length of the carbon chain.  Those contain less than six carbon atoms are soluble in both water and organic solvents.  Aldehydes and ketones that contain six or more carbon atoms are not soluble in water but soluble in organic solvents only.  Solubility of smaller ketones and aldehydes are result of the hydrogen bond formation between the lone pairs of oxygen atom and the hydrogen atom in the water molecule.

(b)

Interpretation Introduction

Interpretation:

The compound that has higher solubility in water among the given pair has to be identified.

Concept Introduction:

Carbonyl groups are the one which contain a double bond between carbon and oxygen atom.  Aldehydes and ketones possess this carbonyl functional group in it.  The structural representation of a carbonyl group can be given as shown below,

Aldehydes contain a carbonyl group that contains a hydrogen atom and a carbon atom bonded to it.  Aldehyde that has one and two carbon atoms are gas at room temperature.  The physical state of aldehyde that contains three carbon atoms to eleven carbon atoms that are not branched is liquid at room temperature.  Aldehydes that contain more than eleven carbon atoms are solid at room temperature.

Ketones contain a carbonyl group that contains two carbon atoms bonded to it.  For a compound to be ketone, a minimum of three carbon atom is required.  Ketones that contain three carbon atoms to eight carbon atoms which have the carbonyl group at the second carbon atom are liquid at room temperature.

Solubility of aldehydes and ketones depend upon the length of the carbon chain.  Those contain less than six carbon atoms are soluble in both water and organic solvents.  Aldehydes and ketones that contain six or more carbon atoms are not soluble in water but soluble in organic solvents only.  Solubility of smaller ketones and aldehydes are result of the hydrogen bond formation between the lone pairs of oxygen atom and the hydrogen atom in the water molecule.