AP Chemistry/Thermodynamics

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Kinetic Energy[edit]

Energy of an object due to the motion of the object. It is represented: KE=1/2mv2.

Enthalpy versus Entropy[edit]

Enthalpy (H) - heat of a system. Negative enthalpy means that the temperature increases. Entropy (S) - randomness of a substance.

Other Stuff[edit]

Specific heat capacity - number of joules of heat needed to warm 1 gram of a substance by 1K. Water's specific heat, in case you didn't remember, is 4.184J/g.

First Law of Thermodynamics = Law of Conservation of energy

Second Law of Thermodynamics - spontaneous reactions increase entropy (randomness).

Gibb's Free Energy[edit]

ΔG = ΔH - T ΔS, where T is temperature in Kelvin. If ΔG is negative, a reaction is spontaneous. Note that some reactions are always spontaneous, some are never, and some depend on the temperature. Also, H is measured in kJ, and S in J.