Chapter 24, Problem 96A

(a)

Interpretation Introduction

Interpretation:

High density of mercury should be identified as physical or chemical property.

Concept introduction:

Any change is either physical or chemical. A physical change brings about a change in the physical property of an object and not its composition. On the other hand chemical change brings about change in composition of object. It is also called chemical reaction.

Answer to Problem 96A

High density of mercury is a physical property.

Explanation of Solution

The formula to calculate density of any object is as follows:

$\text{density}=\frac{\text{mass}}{\text{volume}}$

So it is denoted by unit: gram per milliliter.

Density is directly associated to the mass of an object and inversely associated to the volume of a substance.

Since any variation in density cannot bring about a change in the chemical formula of mercury, so it is a physical property.

(b)

Interpretation Introduction

Interpretation:

Sublimation of solid ${\text{CO}}_{\text{2}}$ at room temperature should be identified as physical or chemical property.

Concept introduction:

Any change is either physical or chemical. A physical change brings about a change in the physical property of an object and not its composition. On the other hand chemical change brings about change in composition of object. It is also called chemical reaction.

Answer to Problem 96A

Sublimation of solid ${\text{CO}}_{\text{2}}$ at room temperature is a physical property.

Explanation of Solution

Change in state of a compound from solid to gas is sublimation. It is a process where only state/ phase changes but composition remains same. So, sublimation of solid ${\text{CO}}_{\text{2}}$ at room temperature is a physicalproperty.

(c)

Interpretation Introduction

Interpretation:

Oxidation of zinc in air should be identified as physical or chemical property.

Concept introduction:

Any change is either physical or chemical. A physical change brings about a change in the physical property of an object and not its composition. On the other hand chemical change brings about change in composition of object. It is also called chemical reaction.

Answer to Problem 96A

Oxidation of zinc in air is chemical property.

Explanation of Solution

Zinc in air reacts with oxygen and forms zinc oxide and tarnishes in appearance. The reaction of zinc with oxygen in air is as follows:

$\text{2Zn}\left(\text{g}\right)+{\text{O}}_{\text{2}}\left(\text{g}\right)\to 2\text{ZnO}\left(\text{s}\right)$

Hence it is a chemical change.

(d)

Interpretation Introduction

Interpretation:

Crystalline nature of white solid sucrose should be identified as chemical or physical property.

Concept introduction:

Any change is either physical or chemical. A physical change brings about a change in the physical property of an object and not its composition. On the other hand chemical change brings about change in composition of object. It is also called chemical reaction.

Answer to Problem 96A

Crystalline nature of white solid sucrose is physical property.

Explanation of Solution

White color, and crystalline state of sucrose defines its physical appearance. No change in its composition is indicated. Hence, crystalline nature of white solid sucrose is physical property.