2023-01-03T03:17:07+03:00[Europe/Moscow] en true <p><strong>First law of thermodynamics</strong></p>, <p>Change in Internal Energy equation</p>, <p>Sign conventions of the First Law of Thermodynamics</p>, <p>Law of energy conservation</p>, <p>The first law is really just a particular iteration of the more universal physical _____.</p>, <p><strong>Second law of thermodynamics</strong></p>, <p><strong>Heat</strong></p>, <p>Heat can never spontaneously transfer energy from a cooler object to a warmer one without ...</p>, <p>SI unit for heat</p>, <p>Alternative units of heat</p>, <p>Conversion between calories and nutritional Calories</p>, <p>Conversion between the four common units of heat</p>, <p>One calorie (little c) is the amount of heat required to ...</p>, <p>One Calorie (big C) is the amount of heat required to ...</p>, <p>There are three means by which heat can transfer energy: _____, _____, and _____.</p>, <p><strong>Conduction</strong></p>, <p>Metals are described as the best heat conductors because ...</p>, <p>Gases tend to be the poorest heat conductors because ...</p>, <p>Conduction requires ...</p>, <p><strong>Convection</strong></p>, <p>Because convection involves flow, ...</p>, <p><strong>Radiation</strong></p>, <p>Unlike conduction and convection, ...</p>, <p><strong>Specific heat </strong>(with abbreviation and units)</p>, <p>The specific heat of liquid water is _____ (J)</p>, <p>Formula relating heat gained/lost to change in temperature</p>, <p>The specific heat of liquid water is _____ (cal)</p>, <p>Mnemonic: The equation for heat transfer, given a specific heat, is the same as ...</p>, <p>When a substance is undergoing a phase change, the heat that is added or removed from the system ...</p>, <p>Phase changes occur at a constant temperature, and the temperature will not begin to change until ...</p>, <p>Phase changes are related to changes in _____, not _____.</p>, <p>When a phase change occurs, the increase in potential energy is due to ...</p>, <p>The average kinetic energy of liquid water at 0°C and solid water at 0°C is _____. </p>, <p>Phase change equation</p>, <p>Phase changes from liquid to solid</p>, <p>Phase changes from solid to liquid</p>, <p><strong>Melting point</strong></p>, <p><strong>Heat of fusion</strong></p>, <p>Phase change from liquid to gas</p>, <p>Phase change from gas to liquid</p>, <p><strong>Boiling point</strong></p>, <p><strong>Heat of vaporization</strong></p>, <p>Phase changes from solid to gas</p>, <p>Phase changes from gas to solid</p>, <p>Work accomplished by a change in displacement is not likely to be motivated by _____.</p>, <p>Special types of thermodynamic processes table</p>, <p>Isothermal process equations</p>, <p>Adiabatic process equations</p>, <p>Isobaric (constant pressure) process equations</p>, <p>Isovolumetric (isochoric) process equations</p>, <p><strong>Isothermal process</strong></p>, <p><strong>Adiabatic process</strong></p>, <p><strong>Isovolumetric (also called Isochoric) process</strong></p>, <p><strong>Isobaric process</strong></p>, <p>Thermodynamic Behaviors of Gases diagram (pressure vs volume)</p>, <p>Isobaric work equation</p>, <p>The specific heat of liquids is generally _____ than that of solids. Why? </p> flashcards
MCAT Physics and Math 3.3: First Law of Thermodynamics

MCAT Physics and Math 3.3: First Law of Thermodynamics

  • First law of thermodynamics

    The first law of thermodynamics states that the change in the total internal energy of a system is equal to the amount of energy transferred in the form of heat to the system, minus the amount of energy transferred from the system in the form of work.

  • Change in Internal Energy equation

    ΔU = QW

    ΔU = change in internal energy

    Q = heat

    W = work

  • Sign conventions of the First Law of Thermodynamics

  • Law of energy conservation

    Energy can be neither created nor destroyed; it can only be changed from one form to another.

  • The first law is really just a particular iteration of the more universal physical _____.

    law of energy conservation

  • Second law of thermodynamics

    Objects in thermal contact and not in thermal equilibrium will exchange heat energy such that the object with a higher temperature will give off heat energy to the object with a lower temperature until both objects have the same temperature at thermal equilibrium

  • Heat

    Heat is defined as the process by which a quantity of energy is transferred between two objects as a result of a difference in temperature.

  • Heat can never spontaneously transfer energy from a cooler object to a warmer one without ...

    ... work being done on the system.

  • SI unit for heat

    joule (J)

  • Alternative units of heat

    calorie (cal), nutritional Calorie (Cal), British thermal unit (BTU)

  • Conversion between calories and nutritional Calories

    1 nutritional Calorie ("big C") = 1000 calories ("little c")

  • Conversion between the four common units of heat

    1 Cal ≡ 103 cal = 4184 J = 3.97 BTU

  • One calorie (little c) is the amount of heat required to ...

    ... raise 1 g of water one degree Celsius.

  • One Calorie (big C) is the amount of heat required to ...

    ... raise 1 kg of water 1 degree Celsius, equal to 1000 calories.

  • There are three means by which heat can transfer energy: _____, _____, and _____.

    conduction, convection, and radiation

  • Conduction

    Conduction is the direct transfer of energy from molecule to molecule through molecular collisions.

  • Metals are described as the best heat conductors because ...

    ... metallic bonds contain a density of atoms embedded in a sea of electrons, which facilitate rapid energy transfer.

  • Gases tend to be the poorest heat conductors because ...

    ... there is so much space between individual molecules that energy-transferring collisions occur relatively infrequently.

  • Conduction requires ...

    ... direct physical contact between the objects.

  • Convection

    Convection is the transfer of heat by the physical motion of a fluid over a material.

  • Because convection involves flow, ...

    ... only liquids and gases can transfer heat by this means.

  • Radiation

    Radiation is the transfer of energy by electromagnetic waves.

  • Unlike conduction and convection, ...

    ... radiation can transfer energy through a vacuum.

  • Specific heat (with abbreviation and units)

    The specific heat (c) of a substance is defined as the amount of heat energy required to raise one gram of a substance by one degree Celsius or one unit kelvin.

  • The specific heat of liquid water is _____ (J)

  • Formula relating heat gained/lost to change in temperature

    q = mcΔT

    q = heat gained/lost

    m = mass

    c = specific heat of the substance

    ΔT = change in temperature

  • The specific heat of liquid water is _____ (cal)

  • Mnemonic: The equation for heat transfer, given a specific heat, is the same as ...

    ... the test you’re studying for!

    q = mcΔT looks a lot like “q equals MCAT.”

  • When a substance is undergoing a phase change, the heat that is added or removed from the system ...

    ... does not result in a change in temperature.

  • Phase changes occur at a constant temperature, and the temperature will not begin to change until ...

    ... all of the substance has been converted from one phase into the other.

  • Phase changes are related to changes in _____, not _____.

    potential energy

    kinetic energy

  • When a phase change occurs, the increase in potential energy is due to ...

    ... an increase in the degrees of freedom of movement.

    Alternatively, one may think of this as an increase in the potential microstates of the molecules.

  • The average kinetic energy of liquid water at 0°C and solid water at 0°C is _____.

    the same

  • Phase change equation

    q = mL

    q = amount of heat gained or lost

    m = mass

    L = heat of transformation, or latent heat

  • Phase changes from liquid to solid

    freezing or solidification

  • Phase changes from solid to liquid

    melting or fusion

  • Melting point

    The temperature at which the solid/liquid phase change occurs.

  • Heat of fusion

    The heat of transformation that occurs at the melting point

  • Phase change from liquid to gas

    boiling, evaporation, or vaporization

  • Phase change from gas to liquid

    condensation

  • Boiling point

    The temperature at which the liquid/gas phase change occurs.

  • Heat of vaporization

    The heat of transformation that occurs at the boiling point.

  • Phase changes from solid to gas

    sublimation

  • Phase changes from gas to solid

    deposition

  • Work accomplished by a change in displacement is not likely to be motivated by _____.

    heat transfer

  • Special types of thermodynamic processes table

  • Isothermal process equations

    ΔU = 0

    Q = W

  • Adiabatic process equations

    Q = 0

    ΔU = −W

  • Isobaric (constant pressure) process equations

    multiple

  • Isovolumetric (isochoric) process equations

    W = 0

    CU = Q

  • Isothermal process

    Constant temperature, and therefore no change in internal energy

  • Adiabatic process

    No heat exchange

  • Isovolumetric (also called Isochoric) process

    No change in volume, and therefore no work accomplished

  • Isobaric process

    Constant pressure

  • Thermodynamic Behaviors of Gases diagram (pressure vs volume)

  • Isobaric work equation

    W = PΔV

  • The specific heat of liquids is generally _____ than that of solids. Why?

    higher

    Liquids have higher degrees of freedom than solids, so there are more ways for liquids to absorb heat w/o experiencing the same change in temperature (far from a rigorous answer)