Chemistry Vocab Thermochemistry

Thermochemistry

the study of how heat is absorbed or evolved during physical and chemical reactions

Temperature

a measure of the average kinetic energy of the particles within a system

Heat (q)

the flow of thermal energy between objects of different temperatures, moving from hot to cold

Endothermic

a process or reaction in which heat is absorbed from the surroundings

Exothermic

a process or reaction in which heat is released into the surroundings

Enthalpy Change (∆H)

the total change in thermal energy during a chemical reaction

Thermochemical Equation

a balanced chemical equation that includes the amount os heat energy absorbed or released

Melting

an endothermic phase change where a solid becomes a liquid

Freezing

an exothermic phase change where a liquid becomes a solid

Vaporization (Boiling)

an endothermic phase change where a liquid becomes a gas

Condensation

an exothermic phase change where a gas becomes a liquid

Sublimation

an endothermic phase change where a solid turns directly into a gas

Deposition

an exothermic phase change where a gas turns directly into a solid

Specific Heat Capacity (C)

the quantity of heat energy needed to change the temperature of one gram of a substance by one degree

Formula (q=mC∆T)

heat energy formula

q

heat energy gained or lost in Joules (J)

m

mass of the substance in grams (g)

C

specific heat capacity (J/g°C)

∆T

change in temperature (Final - Initial)