Chapter 2, Problem 75A

(a)

Interpretation Introduction

Interpretation: Whether iron is an element, compound, or mixture needs to be identified.

Concept Introduction: An element is a substance that cannot be decomposed further into simpler substances by any chemical process. On the other hand, compounds are composed of two or more elements. They can be decomposed into their elemental components. A mixture in solid, liquid, or gaseous form is said to be homogenous if it has the same proportions of components throughout the sample. Thus, in any homogenous mixture, only one phase of matter is observed. In heterogeneous mixtures, the components of the mixture can be easily identified. There is more than one phase and can be seen by the naked eye. It has a non-uniform composition.

Answer to Problem 75A

Element.

Explanation of Solution

The given substance is iron. It is an element because it is made up of only one type of atom. Its atomic number is 26 and its atomic mass is 55.85 amu. It is a metal and belongs to group 8 in the periodic table. It has a high melting point and it is corrosive.

Therefore, iron is an element.

(b)

Interpretation Introduction

Interpretation: Whether distilled water is an element, compound or mixture needs to be identified.

Concept Introduction: An element is a substance that cannot be decomposed further into simpler substances by any chemical process. On the other hand, compounds are composed of two or more elements. They can be decomposed into their elemental components. A mixture in solid, liquid, or gaseous form is said to be homogenous if it has the same proportions of components throughout the sample. Thus, in any homogenous mixture, only one phase of matter is observed. In heterogeneous mixtures, the components of the mixture can be easily identified. There is more than one phase that can be seen by the naked eye. It has a non-uniform composition.

Answer to Problem 75A

Compound.

Explanation of Solution

The given substance is distilled water. The formula of distilled water is ${\text{H}}_{\text{2}}\text{O}$

. It is composed of hydrogen and oxygen. Here, hydrogen and oxygen are combined in a fixed ratio of 2:1. Here, hydrogen and oxygen cannot be separated without any chemical reaction. Since it is made up of more than 2 atoms of elements, it is a compound.

Therefore, distilled water is a compound.

(c)

Interpretation Introduction

Interpretation: Whether laundry detergent is an element, compound or mixture needs to be identified.

Concept Introduction: An element is a substance that cannot be decomposed further into simpler substances by any chemical process. On the other hand, compounds are composed of two or more elements. They can be decomposed into their elemental components. A mixture in solid, liquid, or gaseous form is said to be homogenous if it has the same proportions of components throughout the sample. Thus, in any homogenous mixture, only one phase of matter is observed. In heterogeneous mixtures, the components of the mixture can be easily identified. There is more than one phase that can be seen by the naked eye. It has a non-uniform composition.

Answer to Problem 75A

Mixture (homogeneous).

Explanation of Solution

Laundry detergent is composed of more than one compound. It includes sodium carbonate, sodium silicate, sodium perborate, and other phosphates thus, it is neither an element nor a compound. It is considered a mixture. Since the composition of laundry detergent is uniform throughout, it is a homogenous mixture.

(d)

Interpretation Introduction

Interpretation: Whether sulfur is an element, compound, or mixture needs to be identified.

Concept Introduction: An element is a substance that cannot be decomposed further into simpler substances by any chemical process. On the other hand, compounds are composed of two or more elements. They can be decomposed into their elemental components. A mixture in solid, liquid, or gaseous form is said to be homogenous if it has the same proportions of components throughout the sample. Thus, in any homogenous mixture, only one phase of matter is observed. In heterogeneous mixtures, the components of the mixture can be easily identified. There is more than one phase and can be seen by the naked eye. It has a non-uniform composition.

Answer to Problem 75A

Element.

Explanation of Solution

The given substance is sulfur. It is an element because it is made up of only one type of atom. Its atomic number is 16 and its atomic mass is 32.0 amu. It is a non-metal and belongs to group 16 in the periodic table.

Therefore, sulfur is an element.

(e)

Interpretation Introduction

Interpretation: Whether chicken broth is an element, compound or mixture needs to be identified.

Concept Introduction: An element is a substance that cannot be decomposed further into simpler substances by any chemical process. On the other hand, compounds are composed of two or more elements. They can be decomposed into their elemental components. A mixture in solid, liquid, or gaseous form is said to be homogenous if it has the same proportions of components throughout the sample. Thus, in any homogenous mixture, only one phase of matter is observed. In heterogeneous mixtures, the components of the mixture can be easily identified. There is more than one phase that can be seen by the naked eye. It has a non-uniform composition.

Answer to Problem 75A

Mixture (homogeneous).

Explanation of Solution

Chicken broth contains so many ingredients. It includes water, chicken fat, salt, pepper, and other spices. It is considered a mixture. Its composition is uniform throughout thus, it is considered a homogenous mixture.

(f)

Interpretation Introduction

Interpretation: Whether sodium fluoride is an element, compound or mixture needs to be identified.

Concept Introduction: An element is a substance that cannot be decomposed further into simpler substances by any chemical process. On the other hand, compounds are composed of two or more elements. They can be decomposed into their elemental components. A mixture in solid, liquid, or gaseous form is said to be homogenous if it has the same proportions of components throughout the sample. Thus, in any homogenous mixture, only one phase of matter is observed. In heterogeneous mixtures, the components of the mixture can be easily identified. There is more than one phase that can be seen by the naked eye. It has a non-uniform composition.

Answer to Problem 75A

Compound.

Explanation of Solution

Sodium fluoride has the formula NaF. It is a compound containing Na and F atoms. Here, Na is metal and F is a non-metal. The compound is formed by the transfer of electron from Na to F atoms. Here, Na and F are combined in a fixed ratio of 1:1. Since it is composed of more than one type of element, it is a compound.