Chapter 10, Problem 10.1QP

Define these terms: system, surroundings, thermal energy, chemical energy.

Interpretation Introduction

Interpretation: The terms system, surroundings, thermal energy and chemical energy has to be defined.

Concept Introduction:

The terms system, surroundings, thermal energy and chemical energy are involved in thermodynamic process.

System can be defined as portion of universe and surrounding can be defined as rest of the universe other than the system.

Thermal energy can be defined as internal energy that is seen in the system because of its temperature.

Chemical energy can be defined as the energy that is seen in the chemical bonds of atoms and molecules. The chemical energy occurs as energy released during a chemical reaction

Answer to Problem 10.1QP

System can be defined as portion of universe.

Surrounding can be defined as rest of universe other than the system.

Thermal energy can be defined as internal energy that is seen in the system because of its temperature.

Chemical energy can be defined as the energy that is seen in the chemical bonds of atoms and molecules. The chemical energy occurs as energy released during a chemical reaction

Explanation of Solution

System can be defined as portion of universe. The physical and chemical changes of substance generally constitute a system.

There are types of system in thermodynamics namely,

1. 1. Open system
2. 2. Closed system
3. 3. Isolated system

Open system: The free exchange of matter and energy with its surroundings is called as open system. The exchange of matter in open system takes place either by addition of matter or removal of matter. The exchange of energy is much more complicated than exchange of heat. The exchange of energy takes place through heat and through work.

The figure below shows the transfer of energy and matter.

Figure 1

Closed system: The exchange of energy with its surroundings and not matter is called as closed system. The transfer of energy is similar to that of open system

The figure below shows the transfer of energy in close system

Figure 2

Isolated system: Either exchange of energy or matter takes place with the surroundings is called isolated system.

To define surroundings

Surrounding can be defined as rest of universe other than the system.

Explanation:

Any part of the universe other than the system is called as surroundings.

Consider, the example of acid-base neutralization reaction,

The reactants $\text{HCl}$ and $\text{NaOH}$ are called as system. The container and water in which the reactants are dissolved are called as surroundings.

To define thermal energy

Thermal energy can be defined as internal energy that is seen in the system because of its temperature.

Explanation:

Thermal energy can be defined as internal energy that is seen in the system because of its temperature. Thermal energy deals the unsystematic motion of atoms and molecules.

Its type of kinetic energy that is due to motion. Thermal energy results in substance possessing an internal temperature, which can be measured.

Consider, the example below

Thermometer having degrees in Celsius or Fahrenheit, the particles move faster within an object or system, higher the temperature is recorded.

To define chemical energy

Chemical energy can be defined as the energy that is seen in the chemical bonds of atoms and molecules. The chemical energy occurs as energy released during a chemical reaction.

Explanation:

The form of energy that is stored in chemical bonds of atoms and molecules are called as chemical energy. The chemical energy occurs as energy released during a chemical reaction called as exothermic energy

Examples of matter containing chemical energy are,

1. 1) Coal- Chemical energy is converted into light and heat.
2. 2) Wood- Chemical energy is converted into light and heat. Etc