Chapter 18 Thermodynamics

Question 1

Thermodynamics

Answer 1

The study of heat and its transformation to different forms of energy

Question 2

Absolute zero

Answer 2

The lowest possible temperature that a substance may have; the temperature at which particles of a substance have their minimum kinetic energy.

Question 3

Internal energy

Answer 3

The total energy (kinetic plus potential) of a submicroscopic particles that make up a substance. Changes in internal energy are of principal concern in thermodynamics.

Question 4

First law of thermodynamics

Answer 4

A restatement of the law of energy conservation, applied to systems in which energy is transferred by heat and/ or work. The heat added to a system equals its increase in internal energy plus the external work it does on the environment.

Question 5

Adiabatic process

Answer 5

A process, often of fast expansion or compression, wherein no heat enters or leaves a system.

Question 6

Temperature inversion

Answer 6

A condition in which upward convection of air ceases, often because an upper region of the atmosphere is warmer than the region below it.

Question 7

Second law of thermodynamics

Answer 7

Thermal energy never spontaneously flows from a cold object to a hot object. Also, no machine can be completely efficient in converting heat to work; some of the heat supplied to the machine at high temp is dissipated as waste heat at lower temperature. And finally, all systems tend to become more and more disordered as time goes by.

Question 8

Heat engine

Answer 8

A device that uses heat as input and supplies mechanical work as output, or that uses work as input and moves heat “uphill” from a cooler to a warmer place.

Question 9

Entropy

Answer 9

A measure of the disorder of a system. Whenever energy freely transforms from one form to another, the direction of transformation is toward a state of greater disorder and therefore toward one of great entropy.