Tag: Energy

Introduction

Everything in the universe consists of tiny particles called molecules, which are classified based on the distance and the attractive force between their constituents. Different substances have distinct properties such as mass, temperature, density, volume, pressure, etc. 

The process of transfer of heat is achieved through three different processes in matter, namely, conduction, convection, and radiation. It is studied under thermodynamics, which deals with thermal energy and its relationship to heat, work, temperature, energy, entropy, and other physical properties of matter. 

Isotherms and adiabats

Thermodynamic system

A thermodynamic system is defined as a collection of matter confined within specific boundaries. Within the system, transformations can take place internally. At the same time, interaction with the outside world can occur through the boundaries, which can have a definite permeability. 

Based on the type of the boundary of the thermodynamic system, it can be classified into three categories: isolated system, closed system, and open system. 

• In an isolated system, no energy or matter is exchanged across its boundaries, and no work is performed. An example is items packed in a vacuum bag.
• A closed system allows for energy transformation, but matter cannot cross its boundaries, as seen in a cylinder closed by a valve. 
• And finally, an open system allows for the free exchange of energy and matter across its boundaries, such as a pool filled with water.

Thermodynamic processes

Thermodynamic processes involve an energy transfer between two systems or between systems and their surroundings, resulting in changes in volume, pressure, or temperature. Depending on the type of process, the process can change the energy of the system and perform some work on or by the system.

To classify thermodynamic processes, we look at how they are performed and what conditions they are performed in. 

• An isothermal process is one where the temperature of the system remains constant while energy is exchanged in or out.
• An isobaric process keeps the pressure constant.
• An isochoric process occurs when there is no change in the volume of the system.
• Finally, in an adiabatic process, no heat is exchanged by the systems. We’ll discuss adiabatic processes in detail here.

What is an adiabatic process?

An adiabatic process refers to a thermodynamic process in which, no heat energy is exchanged between the system and the surroundings. To be considered adiabatic, the system must satisfy two conditions.

1. It must be completely isolated. 
2. The process must occur over a short enough time frame, which makes it impossible for heat transfer to take place. 

Work done in adiabatic process

We start with a cylinder with walls made up of an insulating material. We assume that it has a frictionless piston attached to it also made up of an insulating material, effectively preventing heat from escaping. 

Reversible adiabatic process

An adiabatic process is considered reversible if the system can go back to its original state with no alterations. However, this can’t be achieved practically since a reversible adiabatic process does not really exist in nature. But theoretically, such a process is known as an isentropic process and one example of such a process is the adiabatic expansion of a real gas.

Irreversible adiabatic process

If the system cannot return to its original state after the process has occurred, the process is termed irreversible and is accompanied by a change in the entropy of the system. One example would be heat transfer.

Application of adiabatic process

Adiabatic processes occur in the following scenarios:

1. The principle is used in refrigerators.
2. Some processes in a thermal engine are adiabatic in nature. 
3. Compressors and turbines also work on adiabatic principles. 
4. Igloos and thermos flasks are isolated systems and they utilise adiabatic principles.
5. Quantum harmonic oscillators work adiabatically.

Carnot cycle

Summary

This tutorial covered the topic of thermodynamic systems and processes, including the work done in adiabatic processes. The discussion also included the differences between reversible and irreversible adiabatic processes and the various applications of adiabatic processes.

Frequently Asked Questions

1. Give some examples for all thermodynamic processes.

There are four types of thermodynamic processes: isothermal, adiabatic, isobaric, and isochoric. Some examples of these processes include boiling water, refrigeration, the Carnot engine, heat pumps, the freezing of water into ice, pressure cooking, and vertical atmospheric airflow.

2. Differentiate isothermal and adiabatic processes.

3. What is the specific heat capacity?

The specific heat capacity refers to the amount of energy that must be supplied to one mole of a substance to increase its temperature by one degree.

4. What do adiabatic compression and expansion do?

Adiabatic compression leads to an increase in system temperature and adiabatic expansion causes a decrease in temperature.

5. What is the first law of thermodynamics?

The first law relates the internal energy of the system with the heat exchange the work done. According to the first law, internal energy is the difference of the latter two quantities.

Also Read: Adiabatic Processes Derivation

Introduction

The ability to work emanates with energy. For any action, we require energy in the form of mechanical, chemical, electrical, static, kinetic, muscular, and other forms. Understanding the several energy sources is necessary for utilising all forms of energy, which can be obtained from various sources, including both natural and artificial ones. Interestingly, natural energy sources include the sun, wind, tidal, geothermal, and gravitational energies, while artificial energy sources include biomass, coal, petroleum, and a host of others. To ensure that the energy resources survive for a long time, it is crucial to save and use them as effectively as possible. Although not all energy sources release dangerous gases, their use can occasionally lead to pollution. Moreover, energy comes in two forms: traditional and unconventional sources.

Conventional Sources of Energy

Conventional energy sources are non-renewable, which implies that after they have been utilised, they cannot be reused. Coal, oil, natural gas, fuel wood, and nuclear energy are a few examples of traditional/conventional sources of energy. Coal, natural gas, and petroleum account for 90% of the commercial energy produced worldwide, while nuclear power accounts only for 10%.

Types of Conventional Sources of Energy

a. Coal

• Coal, a sedimentary rock in the black-brown range, is the most prevalent conventional energy source and has a long lifespan of 200 years. Long-term exposure to heat and pressure transforms dead plants into lignite and anthracite, which are then finally transformed into coal.
• There are several applications for coal, such as fuel for steam engines in trains and the production of electricity.
• About 70% of the total energy used in our nation is generated by coal.

b. Oil

• Due to the variety of uses for oil, it is one of the most significant conventional energy sources.
• The oil extraction procedure, which entails several processes, is used to obtain the oil.
• Oil is utilised commercially and in a variety of sectors, including the food, cosmetic, and transportation industries.

c. Petroleum and Natural Gas

• Petroleum is made up of Alkanes and cycloalkanes.
• Methane, ethane, propane, butane, and hydrogen sulphide are all components of natural gas.
• Natural gas is created when gas comes into contact with the petroleum layer and is a black liquid when it is in its raw state.
• Petroleum is used to make things like plastic, petrol, and diesel.
• Compared to other fuels, natural gas produces less air pollution.

d. Nuclear Energy

• Nuclear materials that contain radioactive elements are used to create energy.
• 300 or more nuclear reactions are required for the production of nuclear energy.
• Some negative effects of nuclear energy include its radioactivity and danger.
• From one location to another, it is simple to travel by rail or ship. For instance, coal, oil, and natural gas are raw materials.

Advantages of Conventional Sources of Energy

• For any energy, the installation of conventional plants is simple.
• There is no need to wait for energy to be generated because it may be produced quickly depending on the needs.
• Alternative forms of energy are readily accessible and renewable resources that may be utilised again.
• Solar energy, wind energy, tidal energy, geothermal energy, biomass, and solar energy are a few examples of non-conventional sources.

Non-conventional Sources of Energy 

• Alternative forms of energy are readily accessible and renewable resources that may be utilised again.
• Solar energy, wind energy, tidal energy, geothermal energy, biomass, and solar energy are a few examples of non-conventional sources.

Solar Energy

• In solar power plants, sunlight is transformed into electrical energy to produce solar energy.
• Although solar energy is the most significant non-conventional energy source, it is also the least consumed.
• Solar energy comes from renewable resources, is widely accessible, and is non-polluting. 
• Solar ovens, solar panels, solar heaters, and solar cells are a few examples.

Wind Energy

• Turbines are used to generate electricity from wind as a source of energy.
• The power output rises along with the wind speed.
• These wind turbines are situated where the wind speed is strongest and at its highest altitude.
• Wind energy is positioned close to agricultural regions and is pollution-free.

Biomass Energy

• Wood, sewage, plants, animals, and other organic materials are used to create biomass.
• Burning this material releases heat energy, which is then transformed into electrical energy.
• Cooking, lighting, and the production of power are among the uses of biomass.
• A total of 14% of the world’s energy comes from biomass.

Tidal Energy

• Tidal energy is produced by turning the mechanical energy of tides into electricity.
• This energy source can be used in areas that are close to oceans and seas.

Advantages of Non-Conventional Sources of Energy

• These resources are very less expensive and renewable.
• Non-conventional sources are environmentally friendly.
• These resources require low maintenance.
• Offer long-term use as compared to conventional sources.

A comparison between the Conventional and Non-Conventional Sources of Energy.

Conventional Source of Energy	Non-Conventional Source of Energy
Conventional sources of Energy is being used for a longer period.	Non-conventional energy sources have lately been created and are environmentally beneficial.
Conventional resources are a prominent cause of environmental pollution due to the emission of gases and smoke.	Since non-conventional energy is derived from renewable
Non-renewable sources of energy.	Renewable sources of energy.
Examples – Coal, Petroleum, Natural Gas, oil, and Nuclear Energy.	Examples-Wind Energy, Solar Energy, Tidal Energy, Hydropower Energy, and Thermal Energy.

Summary

Conventional sources of energy emit greenhouse gases while producing power and are limited, therefore then-conventional energy sources, which are renewable and environmentally favourable are suitable for sustainability. The major conventional energy sources are coal, oil, petroleum, natural gases, etc. while the non-conventional sources include solar energy, wind energy, tidal energy, biomass energy, etc.

Frequently Asked Questions

1. Why should we Conserve Energy?

Ans: Energy conservation is a measure used to protect and preserve energy sources from becoming extinct. We must save our energy supplies for later use. Utilisation must be reduced to conserve. Our needs are growing daily, yet we only have a limited amount of energy resources. 

2. What is a Renewable Source of Energy?

Ans. Renewable energy comes from naturally occurring, regenerative sources. Renewable energy sources include wind, solar, biomass, thermal, etc. Renewable energy can be continuously replenished without running out.

About 16% of the world’s energy consumption is made up of renewable sources. Renewable energy is a plentiful and sustainable source of power. Sunlight is the most significant and widely available renewable energy source.

3. What are the Advantages of Non-Conventional Sources of Energy over Conventional Sources of Energy?

Ans. The natural limitations of conventional energy sources, which emerged after millions of years and are subject to extinction at any time, make them very vulnerable. The abundance of non-traditional energy sources in nature makes them increasingly significant and practical. Additionally, non-traditional sources of energy are environmentally beneficial and don’t damage or contaminate the environment. The cost of fuel generated from unconventional energy sources is lower than that of traditional energy sources.

Introduction

The measurement of a system or substance’s heat is called its temperature. The pace of an enzyme-catalyzed reaction typically increases as the temperature rises in most chemical processes. Temperature is the internal energy contained within a particular system. Temperature can be measured by a thermometer. Temperature is measured in degrees Celsius, which is written as °C, and can be also measured in Kelvin (K) and Fahrenheit (°F). Temperature alters the states of matter by reducing or increasing the interatomic distances. 

Temperature Effect/Effect of Temperature

In several ways, the temperature has an impact on substances, processes, and enzymes. A substance’s state can be altered by varying its temperature. As the temperature rises, a solid can turn into a liquid, and as the temperature rises more, a liquid can turn into a gas. At high temperatures, a solid can be directly converted into a gas and this process is known as sublimation. Similar to the process where liquids may turn into solids at low temperatures, gases can become liquids by raising pressure while lowering the temperature. The rate of response of the transformation between the different states of matter is also positively or negatively impacted by temperature.

Learn More about Temperature and Heat. Check out more videos in 7th Class Science Lesson no 4.

The Effect of Change of Temperature on Solid State

As the temperature rises, the particles’ kinetic energy rises as well. As a result of the increase in kinetic energy, particles move faster and begin vibrating more quickly. The forces of attraction between the particles are weakened or eliminated by the heat energy. The particles start to travel more freely after leaving their fixed places. At some point, the solid melts and becomes a liquid. The melting point of a solid is the temperature at which it begins to dissolve into a liquid. When two distinct solid objects formed of the same substance are melted, they might combine to form a new one, a process known as fusion.

Effect of Change of Temperature on States of Matter

Heating and cooling are the two primary methods for converting states of matter. By applying heat, a solid can be transformed into a liquid. Similar to how a liquid may become a gas by heating. The opposite is also true; when a gas loses any of its thermal energy, it turns into a liquid. Further, removing a liquid causes its heat energy to solidify. The rising temperature causes a rise in the kinetic energy of the particles and the interspace between them. The force of attraction between particles is reduced by the increase in kinetic energy. 

Effect of Temperature on Pressure

A physical force that is applied to an item by anything in touch with it is called pressure. The pressure can be estimated by the force per unit area. Three variables which affect how much pressure a gas exerts on the walls of the chamber of a container in which it is contained and surrounded by a vacuum. These factors are the quantity of gas within the chamber, the chamber’s size, and the gas’s temperature. The link between the pressure and temperature of gases can be explained, according to the gas law, which states that the pressure of a given volume of a specific gas is precisely proportional to its temperature at a constant volume. This relationship between pressure and temperature is what is meant by the term “pressure-temperature relationship.” It can be modelled as:

  P∝T

A system’s temperature changes cause the molecules in the gas to move more quickly, increasing the pressure on the gas container’s wall. The system’s pressure rises as a result. The pressure likewise lowers when the system’s temperature rises. As a result, for constant volume, the pressure of a given gas is exactly proportional to the temperature.

The gas expands in volume at constant pressure as the temperature rises. The volume of the gas grows because it requires more space to move since the kinetic energy of the molecules increases as the temperature rises.

Effect of Temperature-Examples

The usage of light sticks or glow sticks is one illustration of how temperature affects the speed of chemical reactions. Chemiluminescence, a chemical process, occurs on the light stick. But neither is needed for nor produced by this reaction. The temperature has an impact on its pace. Precipitation reaction, activation energy, etc. are further examples.

Summary

The many states of matter are significantly impacted by temperature. The impact of temperature varies depending on the condition of matter. The kinetic energy of the state increases with temperature, yet the force of attraction varies depending on the state. The various states of matter are also impacted under constant pressure and volume. The pressure of the gas drops while the volume remains constant. The volume of the gas grows with constant pressure.

Frequently asked questions

1. What is the Liquid State of Matter?

Ans: Between the solid and gaseous forms of matter is the liquid state. Ice (solid), liquid as water, and gas as vapor are the three states of water. Although liquids do not have particular shapes, they do have specific volumes. The force of attraction in the liquid state is stronger than that in the gaseous state and weaker than that in the solid state. Atoms in this state have kinetic energies that are higher than those in solids, but lower than those in gases.

2. What Happens when the Temperature of a Gas Increases at Constant Pressure?

Ans. The temperature of a given system or gas container rises as the pressure in that system or container rises. While the pressure remains constant, the temperature rises, the velocity of the gas molecules increases, and the volume of the gas rise. As the gas’ temperature rises, the gas ascends into the atmosphere.

3. What is the Relationship between Pressure and Volume in Boyle’s Law?

Ans: When the temperature is maintained constant, Boyle’s Law states that the pressure exerted by a certain quantity of gas (the number of moles) is inversely proportional to the volume. The volume of the gas reduces with increasing pressure, and vice versa. The molecule tends to approach.