Chapter 14 chemistry vocabulary

Chp 14 vocab chem- McGrawHill 2025

Energy

the capacity to do work or produce heat; which is stored in an object due to its composition or position and kinetic energy, which is the energy of motion.

Law of conservation of energy

states that in any chemical or physical process, energy may change from one to form another, but is neither created nor destroyed

Chemical potential energy

The energy stored in a substance because of its composition; most is released or absorbed as heat during chemical reactions or processes.

Heat

a form of energy that flows from a warmer object to a cooler object

Calorie

The amount of heat required to raise the temperature of one gram of pure water by one degree celsius.

Joule

The SI unit of energy

Specific heat

the amount of heat required to raise the temperature of 1g of a substance 1 degree Celsius

Calorimiter

An insulated device that is used to measure the amount of heat released or absorbed during a physical or chemical process.

Thermochemistry

the study of heat changes that accompany chemical reactions and phase changes

System

in thermochemistry, the specific part of the universe containing the reaction or process being studied

Surroundings

in thermochemistry, includes everything in the universe except the system

Universe

in thermochemistry, is the system plus the surroundings

Enthalpy

The heat content of a system at constant pressure

enthalpy (heat) of reaction

The change in enthalpy for a reaction - the difference between the enthalpy of the substances that exist at the end of the reaction and the enthalpy of the substances present at the start.

Thermochemical equation

a balanced chemical equation that includes the physical states of all reactants and the energy change, usually expressed as the change in enthalpy.

Enthalpy (heat) of combustion

The enthalpy change for the complete burning of one mole of a given substance.

Molar enthalpy (heat) of vaporization

The amount of heat required to vaporize one mole of a liquid

Molar enthalpy (heat) of fusion

the amount of heat required to melt one mole of a solid substance

Hess's law

states that if two or more thermochemical equations can be added to produce a final equation for a reaction, then the sum of the enthalpy changes for the individual reactions is the enthalpy change for the final reaction

Standards enthalpy (heat) of formation

The change in enthalpy that accompanies the formation of one mole of a compound in its standard state from its constituent elements in their standard states.

Spontaneous process

a physical or chemical change that occurs without outside intervention and may require energy to be supplied to begin the process

Entropy

A measure of the number of possible ways that the energy of a system can be distributed; related to the freedom of the system's particles to move and the number of ways they can be arranged.

Second law of thermodynamics

The spontaneous processes always proceed in such a way that the entropy of the universe increases

Free energy

the energy available to do work--the difference between the change in enthalpy and the product of the entropy change and the kelvin temperature