Concept 1: Thermochemistry

Flashcards for Thermochemistry Lecture Review

Thermochemistry

The study of the transfer of energy, as heat, that accompanies both chemical and physical changes.

Chemical Change

A chemical reaction that involves an overall change in energy.

Physical Change

A phase change.

Thermal Energy

The total amount of energy in particles in a sample; dependent on temperature and the number of particles.

Temperature

A measure of the average kinetic energy of the particles in a sample of matter. (KE = 1/2 mv^2)

Kelvin (K)

The standard unit for temperature; K = °C + 273.15

Heat (q)

The thermal energy transferred from an object of higher temperature to an object of lower temperature.

Joule (J)

The unit of heat (and other forms of energy).

calorie (cal)

Another unit for heat; 1 calorie = 4.184 J

Food Calorie (Cal)

Equal to 1 kcal or 1,000 calories.

Specific Heat

The amount of energy required to raise the temperature of one gram of a substance by 1 degree Celsius (or Kelvin).

q = mcΔT

Formula for calculating heat transfer, where q = change in thermal energy, m = mass, c = specific heat, and ΔT = change in temperature.

Conduction

Transfer of heat through matter by direct contact of the particles.

Convection

Transfer of heat through the movement of heated particles (e.g., warm air rising).

Radiation

Transfer of heat through the emission of electromagnetic waves.

Law of Conservation of Energy

Energy cannot be created or destroyed when it changes forms. Also known as the 1st Law of Thermodynamics.

Calorimeter

A tool used to measure the energy absorbed or released as heat in a chemical or physical change.