ThermoChemistry

chemical energy is the attracion between electrons and protons

thermal energy is molecular kinetic energy (translation + rotation + vibration)

q represents the heat transferred into or out of a system, measured in units like Joules or kilojoules

q is positive in endothermic reactions and negative in exothermic reactions, q = q_system

work and q are ways to transfer energy between the system and surroundings

$\Delta$ E = q + W

q is more thermal energy and work is more mechanical energy

W = -P$\Delta$ V

if the system expands $\Delta$ V is positive and W is negative

heat transfer between 2 objects at different temperatures; q(object 1) = -q(object 2) or q(system) = 0 =q(object1) + q(object 2)

cm(T[f]-T[i])

m=mass, c=specific heat

q(reaction) = -q(solution)

$\Delta$ H is in kJ/mol, its the change in enthalpy, which represents the heat absorbed or released during a chemical reaction at constant pressure

fusion is the same as melting

Hess’s law -states that the total enthalpy change for a chemical reaction is the same, regardless of the number of steps or the path taken to complete it

Internal energy (E) and enthalpy (H) are examples of state functions.

the value of a state function depends only on the furrent state of the system (temperature, pressure, number of molecules)

heat and work are not state functions

delta H of formation in its standard state is 0