Chapter 3.1, Problem 3SSC

Interpretation Introduction

Interpretation:

Whether iron and oxygen from rust is a chemical property or physical 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 3SSC

Iron and oxygen from rust is the example of chemical property.

Explanation of Solution

In any changes if the composition of substance is changed then it is an example of chemical property. When iron reacts with oxygen, a new substance will be formed as iron oxide iron. So, it is considered as a chemical change or chemical property.

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

Interpretation Introduction

(b)

Interpretation:

Whether iron being denser than aluminum 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 3SSC

Iron is denser than aluminum is an explain of physical property.

Explanation of Solution

The density of any substance is physical property. The density of the substance is a fixed property for any substance. It explains the consistency of a substance the relative thickness of the substance, and the tight arrangement of the atoms.

Iron is harder as compare to the aluminum. The arrangements of the molecules in iron will be constant and lattice of atoms are not changed that means the density will be higher. Thus, the density of soft material will always be lower. So, this 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

(c)

Interpretation:

Whether magnesium burns brightly when it ignites 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 3SSC

The burning process of magnesium is a chemical property.

Explanation of Solution

When magnesium ignites with oxygen it starts burning with brightness. In this reaction the property of reactant and product is different from each other. Magnesium reacts with oxygen and changes into ash, which is magnesium oxide. The composition will change from the original substance. So, it is considered as a chemical property.

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

Interpretation Introduction

(d)

Interpretation:

Oil and water do not mix is physical property 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 3SSC

The mixing of water and oil is the example of physical property.

Explanation of Solution

When mixing oil and water, oil isstill oil and the water is still water. They retain their physical properties like melting point, boiling point, slipperiness, color, odor, and density. Also, neither substance changes. In this change, no new substance will be formed. So, it is considered as 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 melting point of mercury is $\text{-39°C}$. Whether this 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 3SSC

Mercury melts at $\text{-39°C}$ is the example of the physical property.

Explanation of Solution

The melting point and temperature related properties are expression of the physical property. They are constant for particular substance. The arrangement of the subatomic particle is very tight and not shared by any other atom. But after increasing the temperature, the arrangements of the atoms changes but the composition will be remained same. So, it 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.