Key Concepts in Thermodynamics and Calorimetry

A collection of vocabulary flashcards covering key concepts in thermodynamics and calorimetry based on lecture notes.

bomb calorimeter

A device designed to measure the energy change for processes occurring under conditions of constant volume.

calorie (cal)

Unit of heat; the amount of energy required to raise 1 gram of water by 1 degree Celsius; 1 cal = 4.184 J.

calorimeter

A device used to measure the amount of heat absorbed or released in a chemical or physical process.

calorimetry

The process of measuring the amount of heat involved in a chemical or physical process.

chemical thermodynamics

Area of science that deals with the relationships between heat, work, and all forms of energy associated with chemical and physical processes.

endothermic process

A chemical reaction or physical change that absorbs heat energy.

enthalpy (H)

The sum of a system’s internal energy and the mathematical product of its pressure and volume.

enthalpy change (ΔH)

Heat released or absorbed by a system under constant pressure during a chemical or physical process.

exothermic process

A chemical reaction or physical change that releases heat.

first law of thermodynamics

States that internal energy of a system changes due to heat flow in or out of the system or work done on or by the system.

heat (q)

Transfer of thermal energy between two bodies.

heat capacity (C)

Extensive property that represents the quantity of heat required to increase the temperature by 1 degree Celsius.

Hess’s law

States that if a process can be represented as the sum of several steps, the enthalpy change equals the sum of the enthalpy changes of the steps.

hydrocarbon

A compound composed only of hydrogen and carbon; the major component of fossil fuels.

internal energy (U)

Total of all possible kinds of energy present in a substance or substances.

joule (J)

SI unit of energy; amount of energy used when a force of 1 newton moves an object 1 meter.

kinetic energy

Energy associated with an object's motion, equal to one-half the product of the object's mass and the square of its velocity.

nutritional calorie (Calorie)

Unit for quantifying energy provided by digestion of foods; defined as 1000 cal or 1 kcal.

potential energy

Energy derived from the relative position, composition, or condition of a particle or system of particles.

specific heat capacity (c)

Intensive property that represents the quantity of heat required to raise the temperature of 1 gram of a substance by 1 degree Celsius.

standard enthalpy of combustion

Heat released when one mole of a compound undergoes complete combustion under standard conditions.

standard enthalpy of formation

Enthalpy change of a chemical reaction in which 1 mole of a pure substance is formed from its elements in their most stable states.

standard state

Set of physical conditions accepted as common reference conditions for reporting thermodynamic properties.

state function

Property depending only on the state of a system, and not the path taken to reach that state.

surroundings

All matter other than the system being studied.

system

Portion of matter undergoing a chemical or physical change being studied.

temperature

Intensive property that is a quantitative measure of 'hotness' and 'coldness'.

thermal energy

Kinetic energy associated with the random motion of atoms and molecules.

thermochemistry

Study of measuring the amount of heat absorbed or released during a chemical reaction or physical change.

work (w)

Energy transfer due to changes in external variables such as pressure and volume or causing matter to move against an opposing force.