Chapter 10, Problem 111A

(a)

Interpretation Introduction

Interpretation: Whether “an aspirin tablet is crushed to a powder” is a physical or a chemical change needs to be identified.

Concept Introduction: If a substance changes in only its physical appearance such as size, color, and shape, it is known as a physical change. In a chemical change, one substance combines with other to form a new substance.

Explanation of Solution

If an aspirin tablet is crushed to a powder, there is no new substance formed only physical appearance changes. Thus, it is a physical change.

(b)

Interpretation Introduction

Interpretation: Whether “a red rose turns brown” is a physical or a chemical change needs to be determined.

Concept Introduction: If a substance changes in only its physical appearance such as size, color, and shape, it is known as a physical change. In a chemical change, one substance combines with other to form a new substance.

Explanation of Solution

The change of color from red rose to brown is a chemical change. This is due to fungal attack and this process is not reversible.

(c)

Interpretation Introduction

Interpretation: Whether grape juice turns to wine is a physical or a chemical change needs to be determined.

Concept Introduction: If a substance changes in only its physical appearance such as size, color, and shape, it is known as a physical change. In a chemical change, one substance combines with other to form a new substance.

Explanation of Solution

The formation of wine from grape juice is a chemical change. This process is known as fermentation. This process is not reversible. The complete process involves several steps like harvesting, crushing, fermentation, clarification, and aging. As the process results in the formation of a new substance (wine from grapes), this is a chemical change.

(d)

Interpretation Introduction

Interpretation: Whether “fingernail polish remover evaporates” is a physical or a chemical change needs to be determined.

Concept Introduction: If a substance changes in only its physical appearance such as size, color, and shape, it is known as a physical change. In a chemical change, one substance combines with other to form a new substance.

Explanation of Solution

Evaporation is a physical change. During the evaporation of fingernail polish, no new substance is formed. Here, liquid fingernail polish converts to vapor. Thus, it is a physical change.

(e)

Interpretation Introduction

Interpretation: Whether “a bean seed sprouts” is a physical or a chemical change needs to be determined.

Concept Introduction: If a substance changes in only its physical appearance such as size, color, and shape, it is known as a physical change. In a chemical change, one substance combines with other to form a new substance.

Explanation of Solution

Sprouting is a chemical change as the process can not be reversed and a new substance is formed. The process is the germination of a seed.

(f)

Interpretation Introduction

Interpretation: Whether “a piece of copper beaten into thin sheet” is a physical or a chemical change needs to be determined.

Concept Introduction: If a substance changes in only its physical appearance such as size, color, and shape, it is known as a physical change. In a chemical change, one substance combines with other to form a new substance.

Explanation of Solution

When a piece of copper is beaten into a thin sheet, it is chemical composition does not change. The process only changes the shape of the copper object or its physical appearance. Since no new substance is formed, it is a physical change.