2A.1 Work, Heat & Energy

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What is the system in thermodynamics?

The region outside the area of interest

The area where energy is exchanged

The part of the world of interest (correct)

The area where measurements are made

What type of system allows matter to be transferred through its boundary?

Open system (correct)

Isolated system

Closed system

Surroundings

What is the fundamental physical property in thermodynamics?

Work (correct)

Energy

Temperature

Pressure

What is an example of work in thermodynamics?

Raising a weight against the pull of gravity Signup and view all the answers

What type of system has neither mechanical nor thermal contact with its surroundings?

Isolated system Signup and view all the answers

What can a closed system do with its surroundings?

Transfer energy but not matter Signup and view all the answers

What is the primary difference between heat and work?

Heat is a transfer of energy that makes use of thermal motion, while work makes use of organized motion. Signup and view all the answers

What happens when a system heats its surroundings?

Molecules of the system stimulate the thermal motion of the molecules in the surroundings. Signup and view all the answers

What is the result of the compression of a gas in an adiabatic enclosure?

The gas molecules are accelerated to higher average speeds. Signup and view all the answers

What happens when energy is transferred to the surroundings as heat?

The transfer stimulates random motion of the atoms in the surroundings. Signup and view all the answers

What happens when a system does work?

The system stimulates orderly motion in the surroundings. Signup and view all the answers

What is the primary definition of a process doing work?

Raising a weight somewhere in the surroundings Signup and view all the answers

What is the role of the surroundings in the transfer of energy as work?

The surroundings are used to transfer energy to the system in an organized way. Signup and view all the answers

What is the result of doing work on an otherwise isolated system?

The capacity of the system to do work is increased Signup and view all the answers

What is an example of a chemical reaction that can drive a motor and be used to raise a weight?

A chemical reaction in a cell Signup and view all the answers

What is the term for the transfer of energy as a result of a temperature difference between the system and its surroundings?

Heat Signup and view all the answers

What is the characteristic of a diathermic boundary?

It permits the transfer of energy as heat Signup and view all the answers

What is an exothermic process an example of?

Chemical reaction that releases energy as heat Signup and view all the answers

What happens to the temperature of a system when an endothermic process occurs in an adiabatic container?

The temperature falls Signup and view all the answers

What is the definition of thermal motion?

The disorderly, apparently random, molecular motion in the surroundings Signup and view all the answers

What is the result of an exothermic process in an adiabatic container?

The temperature rises Signup and view all the answers

What is the term for a process in which energy is acquired as heat?

Endothermic process Signup and view all the answers

What is the key characteristic of a system that can expand and raise a weight in the surroundings, despite not allowing matter to be transferred through its boundary?

The system is a closed system that can exchange energy with the surroundings. Signup and view all the answers

What is the primary distinction between a system that allows matter to be transferred through its boundary and one that does not, in terms of their interactions with the surroundings?

The primary distinction is that an open system can exchange matter with the surroundings, whereas a closed system cannot. Signup and view all the answers

What is the significance of the thermodynamic concept of work in relation to the molecular origins of observations?

The concept of work provides a macroscopic perspective that complements the microscopic understanding of molecular origins. Signup and view all the answers

How do the surroundings facilitate the transfer of energy as work in a closed system, and what is the resulting effect on the system?

The surroundings provide an opposing force against which the system can do work, resulting in a change in the system's energy state. Signup and view all the answers

What is the key implication of a system being classified as isolated, in terms of its interactions with the surroundings?

An isolated system has neither mechanical nor thermal contact with the surroundings, meaning it cannot exchange energy or matter. Signup and view all the answers

How does the concept of work relate to the primary objective of thermodynamics, and what is the significance of this relationship?

Work is a fundamental concept in thermodynamics, as it allows for the analysis of energy transformations, which is the primary objective of the field. Signup and view all the answers

What is the fundamental distinction between a system that undergoes an exothermic process in a diathermic container versus an adiabatic container?

In a diathermic container, the energy released as heat is transferred to the surroundings, whereas in an adiabatic container, the energy remains inside the container and results in a permanent rise in temperature. Signup and view all the answers

What is the thermodynamic implication of a system's capacity to do work increasing when work is done on it?

The energy of the system is increased. Signup and view all the answers

In a combustion reaction, what is the direction of energy transfer, and what is the resulting effect on the system's temperature?

Energy is released as heat, and the system's temperature rises. Signup and view all the answers

What is the primary difference between an exothermic process and an endothermic process in terms of energy transfer?

In an exothermic process, energy is transferred to the surroundings as heat, whereas in an endothermic process, energy is transferred from the surroundings as heat. Signup and view all the answers

What is the effect of an endothermic process on the temperature of a system in an adiabatic container?

The temperature of the system decreases. Signup and view all the answers

What is the role of thermal motion in the transfer of energy as heat?

Thermal motion is the disorderly, apparently random, molecular motion that enables the transfer of energy as heat. Signup and view all the answers

What is the key characteristic of a system that has undergone work, in terms of its capacity to do work?

The system's capacity to do work is reduced. Signup and view all the answers

What is the distinction between heat and work in thermodynamic processes?

Work is a transfer of energy that can be harnessed to raise a weight, whereas heat is a transfer of energy as a result of a temperature difference. Signup and view all the answers

What is the outcome of an exothermic process in a diathermic container, in terms of the system's temperature and the surroundings?

The system's temperature remains constant, and energy is transferred to the surroundings as heat. Signup and view all the answers

What is the thermodynamic implication of a system's energy increasing due to work being done on it?

The system's capacity to do work is increased. Signup and view all the answers

What is the underlying mechanism that enables a system to do work on its surroundings, and how does it differ from the mechanism of heat transfer?

The underlying mechanism that enables a system to do work on its surroundings is the transfer of energy that makes use of organized motion in the surroundings. This differs from the mechanism of heat transfer, which is the transfer of energy that makes use of thermal motion in the surroundings. Signup and view all the answers

In the context of thermodynamics, what is the significance of the randomization of molecular directions during collisions, and how does it relate to the compression of a gas in an adiabatic enclosure?

The randomization of molecular directions during collisions is significant because it leads to the thermal motion of the gas molecules, whereas the motion of the atoms of the compressing weight is orderly. This is evident in the compression of a gas in an adiabatic enclosure, where the orderly motion of the atoms of the weight stimulates thermal motion in the gas. Signup and view all the answers

How does the transfer of energy from the surroundings to the system differ from the transfer of energy from the system to the surroundings, and what is the role of thermal motion in these processes?

The transfer of energy from the surroundings to the system makes use of random motion (thermal motion) in the surroundings, whereas the transfer of energy from the system to the surroundings stimulates random motion in the surroundings. In both cases, thermal motion plays a crucial role in the energy transfer. Signup and view all the answers

What is the role of the surroundings in identifying whether energy transfer is in the form of work or heat, and how does this relate to the motion of atoms in the surroundings?

The surroundings play a crucial role in identifying whether energy transfer is in the form of work or heat, as the distinction is made based on the type of motion in the surroundings. Energy transfer that makes use of organized motion in the surroundings is classified as work, while energy transfer that makes use of thermal motion in the surroundings is classified as heat. Signup and view all the answers

In the context of thermodynamics, what is the significance of the term 'organized motion' in the surroundings, and how does it relate to the concept of work?

The term 'organized motion' in the surroundings refers to the motion of atoms or electrons in a specific direction, which is a characteristic of work. When a system does work, it stimulates organized motion in the surroundings, whereas when energy is transferred as heat, it stimulates thermal motion in the surroundings. Signup and view all the answers

How does the compression of a gas in an adiabatic enclosure illustrate the distinction between work and heat, and what is the role of the weight in this process?

The compression of a gas in an adiabatic enclosure illustrates the distinction between work and heat, as the orderly motion of the atoms of the compressing weight does work on the system, while the effect of the incoming piston is to accelerate the gas molecules to higher average speeds, resulting in thermal motion. The weight plays a crucial role in stimulating both orderly motion and thermal motion. Signup and view all the answers