Chapter U5.2, Problem 4E

(a)

Interpretation Introduction

Interpretation:

The part of the system in the given reaction is to be listed.

Concept introduction:

The system is the part where the reaction takes place.

Surroundings are the rest of the area of the universe.

Answer to Problem 4E

• $CuS{O}_4(s)$
• $H_{2}O(l)$
• $CuS{O}_4.5H_{2}O(s)$

Explanation of Solution

Copper sulfate combines with water to form copper sulfate pentahydrate, so the system contains $CuS{O}_4(s)$ , $H_{2}O(l)$ and $CuS{O}_4.5H_{2}O(s)$ .

(b)

Interpretation Introduction

Interpretation:

The things that are in the surroundings of the system in the given reaction is to be listed.

Concept introduction:

The system is the part where the reaction takes place.

Surroundings are the rest of the area of the universe.

Answer to Problem 4E

• Air
• Lab in which the experiment is done
• Lab instruments

Explanation of Solution

Surroundings are the area that is not the part of the system.

• Air
• Lab in which experiment is done

(c)

Interpretation Introduction

Interpretation:

The substance which is at a lower temperature in the given reaction is to be listed.

Concept introduction:

The system is the part where the reaction takes place.

Surroundings are the rest of the area of the universe.

Whenever there is a release of energy, the temperature of the reaction mixture rises.

Answer to Problem 4E

As the temperature is increased from $19°Cto48°C$ , $CuS{O}_4(s)$ is at a lower temperature than $CuS{O}_4.5H_{2}O(s)$ .

Explanation of Solution

(d)

Interpretation Introduction

Interpretation:

The observation when the beaker is touched is to be explained.

Concept introduction:

The system is the part where the reaction takes place.

Surroundings are the rest of the area of the universe.

Whenever there is a release of energy, the temperature of the reaction mixture rises.

Answer to Problem 4E

It feels hot.

Explanation of Solution

$CuS{O}_4(s)$ is the reactant and $CuS{O}_4.5H_{2}O(s)$ is the product and the reaction occurs with an increase in temperature. So, the apparatus in which the reaction is taking place will become hot.

(e)

Interpretation Introduction

Interpretation:

Whether the given reaction is endothermic or exothermic needs to be determined.

Concept introduction:

The system is the part where the reaction takes place.

Surroundings are the rest of the area of the universe.

Whenever there is a release of energy, the temperature of the reaction mixture rises.

Answer to Problem 4E

The process is exothermic.

Explanation of Solution

The increase in temperature of the reaction mixture suggests that there is a release of energy. Therefore, the reaction is exothermic.

(f)

Interpretation Introduction

Interpretation:

The evidence that heat is transferred to the surroundings in the given reaction is to be listed.

Concept introduction:

The system is the part where the reaction takes place.

Surroundings are the rest of the area of the universe.

Whenever there is a release of energy, the temperature of the reaction mixture rises.

Answer to Problem 4E

The beaker feels hot. So, the energy is transferred from the system to the surrounding.

Explanation of Solution

The increase in temperature of the reaction mixture suggests that there is a release of energy. Therefore, the reaction is exothermic. As the beaker containing reaction mixture becomes hot, the heat is transferred to the surroundings.