Chapter 13, Problem 1P

For each of the following processes, identify the systemand the surroundings. Identify those processes that arespontaneous. For each spontaneous process, identify theconstraint that has been removed to enable the process to
occur:

1. Ammonium nitrate dissolves in water.
2. Hydrogen and oxygen explode in a closed bomb.
3. A rubber band is rapidly extended by a hangingweight.
4. The gas in a chamber is slowly compressed by aweighted piston.
5. A glass shatters on the floor.

Interpretation Introduction

Interpretation: The system and surrounding for the process needs to be identified in which ammonium nitrate dissolves in water. The constraint that must be removed to enable the process to occur spontaneously needs to be identified.

Concept Introduction: For a given process, a specific part of the universe which is under the observation is known as the system and the rest of the universe other than the system is known as surroundings.

Explanation of Solution

When ammonium nitrate is dissolved in water, the following reaction takes place:

  ${\text{NH}}_{\text{4}}{\text{NO}}_{\text{3}}\left(s\right)\to {\mathrm{NH}}_4^{+}\left(aq\right)+{\text{NO}}_3^{-}\left(aq\right)$

Here, system will be reactants and products of the reaction which takes place. Thus, solid ammonium nitrate, water and ammonium and nitrate ions will be system. The surrounding of the reaction will be the beaker or flask in which the reaction takes place.

The given process is spontaneous only when water and ammonium nitrate come in contact.

Interpretation Introduction

Interpretation: The system and surrounding for the process needs to be identified in which hydrogen and oxygen explode in a closed bomb. The constraint that must be removed to enable the process to occur spontaneously needs to be identified.

Concept Introduction: For a given process, a specific part of the universe which is under the observation is known as the system and the rest of the universe other than the system is known as surroundings.

Explanation of Solution

When hydrogen and oxygen explode in a closed bomb, these are products and form the system. The closed bomb will be the surrounding.

When there is no constraint in the closed bomb, the reaction between hydrogen and oxygen will be spontaneous.

Interpretation Introduction

Interpretation: The system and surrounding for the process needs to be identified in which a rubber band is rapidly extended by hanging weight. The constraint that must be removed to enable the process to occur spontaneously needs to be identified.

Concept Introduction: For a given process, a specific part of the universe which is under the observation is known as the system and the rest of the universe other than the system is known as surroundings.

Explanation of Solution

In the given process, the rubber band will be the system as weight is hanged on it and it undergoes rapid extension.

The things other than the rubber will be the surrounding like the weight.

The extension of rubber band is a spontaneous process when the constraint or any support which is below the hanging weight is removed.

Interpretation Introduction

Interpretation: The system and surrounding for the process needs to be identified in which gas in chamber is slowly compressed by weighted piston. The constraint that must be removed to enable the process to occur spontaneously needs to be identified.

Concept Introduction: For a given process, a specific part of the universe which is under the observation is known as the system and the rest of the universe other than the system is known as surroundings.

Explanation of Solution

In the given process, the gas inside the chamber will be the system. The chamber and the weighted piston will be the surrounding. The compression of the gas is a spontaneous process only when an external pressure that is applied on the piston is more than the internal pressure of the gas.

Interpretation Introduction

Interpretation: The system and surrounding for the process needs to be identified in which a glass shatters on the floor. The constraint that must be removed to enable the process to occur spontaneously needs to be identified.

Concept Introduction: For a given process, a specific part of the universe which is under the observation is known as the system and the rest of the universe other than the system is known as surroundings.

Explanation of Solution

In the given process of shattering of glass on the floor, the glass is system. The floor on which the glass shatters is the surrounding. This process is spontaneous when glass and the floor comes in contact with each other.