Chapter 1, Problem 1Q

Interpretation Introduction

(a)

Interpretation:

The solubility of malic acid in water needs to be explained.

Concept Introduction:

Organic compounds are mainly composed of C and H atoms. It is the branch of chemistry that deals with preparation, reactions, and properties of organic compounds. The atom or group of atoms which are responsible for all special chemical and physical properties of a substance is called as a functional group. These groups are bonded to the parent carbon chain of the organic molecule.

Organic compounds are mainly covalent compounds in which C-C, C-H and C-X bonds are present. Here 'X' indicates hetero atom which is present in functional group. The C-C and C-H bonds are non-polar covalent bonds as the difference between the electronegativity of C and H is very less. On the contrary the polarity of C-X bond depends on the electronegativity of X. If X is O, N or halogen, the C-X bond will be a polar covalent bond that makes the polar organic molecule.

Answer to Problem 1Q

Malic acid is soluble in water.

Explanation of Solution

A polar covalent molecule will be soluble in water whereas a non-polar covalent compound will be insoluble in water based on the concept of "Like dissolves like". Some of the polar compounds are also not soluble in water as they cannot form hydrogen bonding with water molecules.

The structure of malic acid is as follows:

  

Malic acid is a polar molecule due to the presence of two -COOH group in the molecule. Hence, it is soluble in water as it can form Hydrogen-bond with water molecule.

Interpretation Introduction

(b)

Interpretation:

The solubility of naphthalene in water needs to be explained.

Concept Introduction:

Organic compounds are mainly composed of C and H atoms. It is the branch of chemistry that deals with preparation, reactions, and properties of organic compounds. The atom or group of atoms which are responsible for all special chemical and physical properties of a substance is called as a functional group. These groups are bonded to the parent carbon chain of the organic molecule.

Organic compounds are mainly covalent compounds in which C-C, C-H and C-X bonds are present. Here 'X' indicates hetero atom which is present in functional group. The C-C and C-H bonds are non-polar covalent bonds as the difference between the electronegativity of C and H is very less. On the contrary the polarity of C-X bond depends on the electronegativity of X. If X is O, N or halogen, the C-X bond will be a polar covalent bond that makes the polar organic molecule.

Answer to Problem 1Q

Naphthalene is insoluble water.

Explanation of Solution

The structure of naphthalene is as follows:

  

Naphthalene is a non-polar molecule as it is only composed C and H with two ring structures. Hence it is insoluble in water as it cannot form Hydrogen-bond with water molecule.

Interpretation Introduction

(c)

Interpretation:

The solubility of amphetamine in ethyl alcohol needs to be determined.

Concept Introduction:

Organic compounds are mainly composed of C and H atoms. It is the branch of chemistry that deals with preparation, reactions, and properties of organic compounds. The atom or group of atoms which are responsible for all special chemical and physical properties of a substance is called as a functional group. These groups are bonded to the parent carbon chain of the organic molecule.

Organic compounds are mainly covalent compounds in which C-C, C-H and C-X bonds are present. Here 'X' indicates hetero atom which is present in functional group. The C-C and C-H bonds are non-polar covalent bonds as the difference between the electronegativity of C and H is very less. On the contrary the polarity of C-X bond depends on the electronegativity of X. If X is O, N or halogen, the C-X bond will be a polar covalent bond that makes the polar organic molecule.

Answer to Problem 1Q

Amphetamine is soluble in ethyl alcohol.

Explanation of Solution

The structure of amphetamine is as follows:

  

Amphetamine is a polar molecule as it contains one −NH₂group and it can form hydrogen bond with water and ethanol. Hence, it is soluble in ethanol.

Interpretation Introduction

(d)

Interpretation:

The solubility of Aspirin in water needs to be explained.

  

Concept Introduction:

Organic compounds are mainly composed of C and H atoms. It is the branch of chemistry that deals with preparation, reactions, and properties of organic compounds. The atom or group of atoms which are responsible for all special chemical and physical properties of a substance is called as a functional group. These groups are bonded to the parent carbon chain of the organic molecule.

Organic compounds are mainly covalent compounds in which C-C, C-H and C-X bonds are present. Here 'X' indicates heteroatom which is present in functional group. The C-C and C-H bonds are non-polar covalent bonds as the difference between the electronegativity of C and H is very less. On the contrary the polarity of C-X bond depends on the electronegativity of X. If X is O, N or halogen, the C-X bond will be a polar covalent bond that makes the polar organic molecule.

Answer to Problem 1Q

Aspirin is slightly soluble in water.

Explanation of Solution

The structure of aspirin is as follows:

  

Aspirin is slightly soluble in water. Aspirin is a polar molecule as it contains one −COOHgroup and it can form hydrogen bond with water,yet the solubility is quite less due to bulky size of molecule.

Interpretation Introduction

(e)

Interpretation:

The solubility of succinic in hexane needs to be explained.

Concept Introduction:

Organic compounds are mainly composed of C and H atoms. It is the branch of chemistry that deals with preparation, reactions, and properties of organic compounds. The atom or group of atoms which are responsible for all special chemical and physical properties of a substance is called as a functional group. These groups are bonded to the parent carbon chain of the organic molecule.

Organic compounds are mainly covalent compounds in which C-C, C-H and C-X bonds are present. Here 'X' indicates heteroatom which is present in functional group. The C-C and C-H bonds are non-polar covalent bonds as the difference between the electronegativity of C and H is very less. On the contrary the polarity of C-X bond depends on the electronegativity of X. If X is O, N or halogen, the C-X bond will be a polar covalent bond that makes the polar organic molecule.

Answer to Problem 1Q

Succinic acid is insoluble in hexane.

Explanation of Solution

The structure of succinic acid is as follows:

  

Succinic acid is a polar molecule as it contains two −COOHgroups. Due to polar nature of molecule, it is soluble in water but insoluble in organic solvents like hexane.

Interpretation Introduction

(f)

Interpretation:

The solubility of ibuprofen in diethyl ether needs to be explained.

Concept Introduction:

Organic compounds are mainly composed of C and H atoms. It is the branch of chemistry that deals with preparation, reactions, and properties of organic compounds. The atom or group of atoms which are responsible for all special chemical and physical properties of a substance is called as a functional group. These groups are bonded to the parent carbon chain of the organic molecule.

Organic compounds are mainly covalent compounds in which C-C, C-H and C-X bonds are present. Here 'X' indicates heteroatom which is present in functional group. The C-C and C-H bonds are non-polar covalent bonds as the difference between the electronegativity of C and H is very less. On the contrary the polarity of C-X bond depends on the electronegativity of X. If X is O, N or halogen, the C-X bond will be a polar covalent bond that makes the polar organic molecule.

Answer to Problem 1Q

Ibuprofen is soluble in diethyl ether.

Explanation of Solution

The structure of ibuprofen is as follows:

  

Although ibuprofen contains one polar −COOH group yet due to bulky structure, it is overall non-polar molecule and can dissolve in organic solvents such as ether, benzene etc.

Interpretation Introduction

(g)

Interpretation:

The solubility of 1-decanol in water needs to be explained.

Concept Introduction:

Organic compounds are mainly composed of C and H atoms. It is the branch of chemistry that deals with preparation, reactions, and properties of organic compounds. The atom or group of atoms which are responsible for all special chemical and physical properties of a substance is called as a functional group. These groups are bonded to the parent carbon chain of the organic molecule.

Organic compounds are mainly covalent compounds in which C-C, C-H and C-X bonds are present. Here 'X' indicates heteroatom which is present in functional group. The C-C and C-H bonds are non-polar covalent bonds as the difference between the electronegativity of C and H is very less. On the contrary the polarity of C-X bond depends on the electronegativity of X. If X is O, N or halogen, the C-X bond will be a polar covalent bond that makes the polar organic molecule.

Answer to Problem 1Q

1-decanol is insoluble in water.

Explanation of Solution

The molecular formula of 1-decanol is as follows:

  ${\text{CH}}_{\text{3}}{\left({\text{CH}}_{\text{2}}\right)}_{\text{8}}{\text{CH}}_{\text{2}}\text{OH}$

1-decanol is a polar compound with −OH group yet it is insoluble in water due to lack of hydrogen bonds between 1-decanol and water molecules. This is because of long hydrophobic C chain of 1-decanol molecule that prevents the formation of hydrogen bonding.