Chapter 3, Problem 86A

Interpretation Introduction

(a)

Interpretation:

Whether pure drinking water is an element, compound or a homogeneous or a heterogeneous mixture needs to be determined.

Concept introduction:

Element is a pure substance that cannot be broken further into simpler units by any chemical means. All the atoms are identical here.

Compounds are made up of different elements in a fixed ratio.

Homogeneous mixture is the mixture of two or more substances that are not separable or they are present in the same phase, as the mixture of two gases.

Heterogeneous mixtures are separable and are generally in different phases as sand water, or a mixture of two solids that are separable.

Answer to Problem 86A

Pure drinking water is a compound.

Explanation of Solution

Compounds are made up of different elements in a fixed ratio.

Pure drinking water is a compound as the hydrogen and oxygen combined together in a fixed ratio to form water molecule.

(b)

Interpretation Introduction

Interpretation:

Whether salt water is an element, compound or a homogeneous or a heterogeneous mixture needs to be determined.

Concept introduction:

Element is a pure substance that cannot be broken further into simpler units by any chemical means. All the atoms are identical here.

Compounds are made up of different elements in a fixed ratio.

Homogeneous mixture is the mixture of two or more substances that are not separable or they are present in the same phase, as the mixture of two gases.

Heterogeneous mixtures are separable and are generally in different phases as sand water, or a mixture of two solids that are separable.

Answer to Problem 86A

Salt water is a homogeneous mixture.

Explanation of Solution

Homogeneous mixture is the mixture of two or more substances that are not separable or they are present in the same phase, as the mixture of two gases.

The Salt present in salty water is miscible as once dissolved cannot be seen or separated. They can only be separated by distillation. Hence the salt water is considered to be a homogeneous mixture.

(c)

Interpretation Introduction

Interpretation:

Whether helium is an element, compound or a homogeneous or a heterogeneous mixture needs to be determined.

Concept introduction:

Element is a pure substance that cannot be broken further into simpler units by any chemical means. All the atoms are identical here.

Compounds are made up of different elements in a fixed ratio.

Homogeneous mixture is the mixture of two or more substances that are not separable or they are present in the same phase, as the mixture of two gases.

Heterogeneous mixtures are separable and are generally in different phases as sand water, or a mixture of two solids that are separable.

Answer to Problem 86A

Helium is an element.

Explanation of Solution

Element is a pure substance that cannot be broken further into simpler units by any chemical means. All the atoms are identical here.

As helium gas that is made of only on eking of atoms that cannot be broken into simpler units. So, are considered as an element.

(d)

Interpretation Introduction

Interpretation:

Whether sea water is an element, compound or a homogeneous or a heterogeneous mixture needs to be determined.

Concept introduction:

Element is a pure substance that cannot be broken further into simpler units by any chemical means. All the atoms are identical here.

Compounds are made up of different elements in a fixed ratio.

Homogeneous mixture is the mixture of two or more substances that are not separable or they are present in the same phase, as the mixture of two gases.

Heterogeneous mixtures are separable and are generally in different phases as sand water, or a mixture of two solids that are separable.

Answer to Problem 86A

Sea water is a heterogeneous mixture.

Explanation of Solution

Heterogeneous mixtures are separable and are generally in different phases as sand water, or a mixture of two solids that are separable.

Sea water is considered to be a heterogeneous mixture as it contains the mixture of salt and some other size of impurities. They also contain the mixture of several gases.