Thermochemistry and Energy Changes in Chemical Reactions

These flashcards cover key vocabulary related to thermochemistry, energy changes in chemical reactions, calorimetry, and related concepts.

Thermochemistry

The study of energy changes that occur during chemical reactions.

Endothermic Process

A thermochemical process in which energy flows into the system from the surroundings.

Exothermic Process

A thermochemical process in which energy flows from the system into the surroundings.

Internal Energy (E)

The sum of all the kinetic and potential energies of all the components of a system.

Enthalpy (H)

The sum of the internal energy and the pressure-volume product of a system; H = E + PV.

Heat Capacity (C)

The quantity of energy needed to raise the temperature of an object by 1°C.

Molar Heat Capacity (cP)

The quantity of energy required to raise the temperature of 1 mole of a substance by 1°C.

Specific Heat (cs)

The quantity of energy required to raise the temperature of 1 g of a substance by 1°C.

Hess's Law

The principle that the enthalpy of reaction for a process that is the sum of two or more other reactions is equal to the sum of the enthalpy changes for the component reactions.

Standard Enthalpy of Formation (DH° f)

The enthalpy change that occurs when 1 mole of a substance is formed from its elements in their standard states.

Calorimetry

The measurement of the quantity of energy transferred during a physical change or chemical process.

Fuel Value

The amount of energy released during the complete combustion of 1 g of a fuel.

Food Value

The quantity of energy produced when a material consumed by an organism for sustenance is burned completely, typically in Calories (kilocalories) per gram of food.

Hydrogen Bonding

Attractive forces between molecules, significantly influencing the behavior and properties of water.

Thermal Equilibrium

A condition in which no further energy transfer occurs between two objects in thermal contact.

Calorimeter Constant (Ccalorimeter)

The heat capacity of a calorimeter.

Thermodynamic Systems

Classified as isolated, closed, or open depending on their interaction with surroundings.

Heat Transfer

The process of energy moving from a warmer object to a cooler one.

Pressure-Volume Work (P-V Work)

Work associated with the expansion or compression of a gas.