Chapter 3, Problem 38A

Interpretation Introduction

Interpretation:

Aluminum has a silvery color whether it is a physical or chemical property needs to be explained.

Concept introduction:

The nature of any substance is explained by their chemical properties and physical properties.

A physical property describes the physical changes of a substance. Physical change is a temporary change; it is a reversible change. For example, color, mass, volume, etc.

A chemical property describes how a substance reacts with other substances. In a chemical change, a new substance is formed and absorption of energy or loss of energy occurs; it is an irreversible change. For example, rusting, dissolving, etc.

Answer to Problem 38A

Aluminum has silvery color is a physical property.

Explanation of Solution

The physical property is fixed for particular substances, while chemical property changes under the different conditions. The chemical property varies for a particular compound.

The color explains the physical appearance of the substance. So, Aluminum has silvery color is a physical property.

In a chemical change, important point is the formation of a new substance; in the given example, no new substance is formed. So, it is not considered in a chemical change.

Interpretation Introduction

(b)

Interpretation:

The gold has a density ${\text{19g/cm}}^{\text{3}}$ whether it is a physical or chemical property needs to be determined.

Concept introduction:

The nature of any substance is explained by their chemical properties and physical properties.

A physical property describes the physical changes of a substance. Physical change is a temporary change; it is a reversible change. For example, color, mass, volume, etc.

A chemical property describes how a substance reacts with other substances. In a chemical change, a new substance is formed and absorption of energy or loss of energy occurs; it is an irreversible change. For example, rusting, dissolving, etc.

Answer to Problem 38A

The gold has a density ${\text{19g/cm}}^{\text{3}}$ is a physical property.

Explanation of Solution

If the amount of substance increases or decreases, the density remains the same for substance. The density is the ratio of two extensive properties, mass, and volume. Density is fixed for any substance. So, the gold has a density ${\text{19g/cm}}^{\text{3}}$ is a physical property

In a chemical change, important point is the formation of a new substance; in the given example, no new substance is formed. So, it is not considered in a chemical change.

(c)

Interpretation Introduction

Interpretation:

Sodium ignites when dropped in water whether it is a physical or chemical property needs to be explained.

Concept introduction:

The nature of any substance is explained by their chemical properties and physical properties.

A physical property describes the physical changes of a substance. Physical change is a temporary change; it is a reversible change. For example, color, mass, volume, etc.

A chemical property describes how a substance reacts with other substances. In a chemical change, a new substance is formed and absorption of energy or loss of energy occurs; it is an irreversible change. For example, rusting, dissolving, etc.

Answer to Problem 38A

The process of ignites sodium in water is a chemical property.

Explanation of Solution

Sodium is metal and when it reacts with water, it ignites and releases hydrogen gas. In this reaction, the property of reactant and product is different from each other. In this reaction new substance is formed. So, it is considered as chemical property.

The statement in the given question is an irreversible process. So, it is not considered as physical change.

Interpretation Introduction

(d)

Interpretation:

Water boils at ${\text{100}}^{\text{°}}\text{C}$ whether it is a physical property or chemical property needs to be explained.

Concept introduction:

The nature of any substance is explained by their chemical properties and physical properties.

A physical property describes the physical changes of a substance. Physical change is a temporary change; it is a reversible change. For example, color, mass, volume, etc.

A chemical property describes how a substance reacts with other substances. In a chemical change, a new substance is formed and absorption of energy or loss of energy occurs; it is an irreversible change. For example, rusting, dissolving, etc.

Answer to Problem 38A

Water boils at ${\text{100}}^{\text{°}}\text{C}$ is the physical property

Explanation of Solution

The boiling point of water is a constant value. At temperature ${\text{100}}^{\text{°}}\text{C}$ water starts changing its state from liquid to vapor phase. It does not depend on the quantity of the substance. So, it is the physical property

In a chemical change, important point is the formation of a new substance; in the given example, no new substance is formed. So, it is not considered in a chemical change.

Interpretation Introduction

(e)

Interpretation:

The process of tarnish silver is a physical or chemical property needs to be determined.

Concept introduction:

The nature of any substance is explained by their chemical properties and physical properties.

A physical property describes the physical changes of a substance. Physical change is a temporary change; it is a reversible change. For example, color, mass, volume, etc.

A chemical property describes how a substance reacts with other substances. In a chemical change, a new substance is formed and absorption of energy or loss of energy occurs; it is an irreversible change. For example, rusting, dissolving, etc.

Answer to Problem 38A

Tarnishing of silver is the chemical property.

Explanation of Solution

When the silver reacts with atmospheric sulfur it changes and form a new substance in the form of sulfide. So, it is a chemical property.

The statement in the given question is an irreversible process. So, it is not considered as physical change.

Interpretation Introduction

(f)

Interpretation:

Mercury is liquid at room temperature, whether it is a physical property or chemical property needs to be explained.

Concept introduction:

The nature of any substance is explained by their chemical properties and physical properties.

A physical property describes the physical changes of a substance. Physical change is a temporary change; it is a reversible change. For example, color, mass, volume, etc.

A chemical property describes how a substance reacts with other substances. In a chemical change, a new substance is formed and absorption of energy or loss of energy occurs; it is an irreversible change. For example, rusting, dissolving, etc.

Answer to Problem 38A

Mercury is a liquid at room temperature is a physical property.

Explanation of Solution

The state of matter is a physical property. Mercury is found in a liquid state that explains the physical appearance of the compound. The state of matter can be transformed into other states but the composition of the compound does not change. So, it is an example of physical property.

In a chemical change, important point is the formation of a new substance; in the given example, no new substance is formed. So, it is not considered in a chemical change.