AP Chemistry Chapter 5 - Thermodynamics Flashcards

Kinetic Energy

• Kinetic energy (Ek) is calculated using the formula Ek = 1/2mv², where m is mass and v is velocity.

Change in Internal Energy

• The change in internal energy (ΔE) is determined by the formula ΔE = Efinal - Einitial, indicating the difference between final and initial energy states.

First Law of Thermodynamics

• The First Law of Thermodynamics states that the change in internal energy (ΔE) is the sum of heat exchanged (q) and work done (w), expressed as ΔE = q + w.

Pressure-Volume Work

• Pressure-volume work can be described by the equation w = -P ΔV, where P is pressure and ΔV is the change in volume.

Enthalpy Change at Constant Pressure

• Enthalpy change (ΔH) at constant pressure is equivalent to the heat exchanged, represented as ΔH = q.

Heat Gained or Lost (Calorimetric Thermochemistry)

• The heat gained or lost in calorimetry can be calculated using q = Cs x m x ΔT, where Cs is specific heat, m is mass, and ΔT is the change in temperature.

Standard Enthalpy Change of a Reaction (Hess's Law)

• The standard enthalpy change (ΔH°rxn) for a reaction can be calculated with Hess's Law: ΔH°rxn = ∑nΔH°f (products) - ∑mΔH°f (reactants).

Electrical Potential Energy

• Electrical potential energy (Eel) between two charges is given by Eel = (K x Q1 x Q2)/d, where K is the Coulomb's constant, Q1 and Q2 are the charges, and d is the distance between them.

Calorie to Joule Conversion Factor

• Energy conversion between calories and joules is defined by 1 calorie = 4.184 J.

Specific Heat of Liquid Water

• The specific heat of liquid water is 1 calorie/g·°C, equivalent to 4.184 J/g·°C.

Heat of Fusion

• The heat of fusion is calculated using q = m x ΔHfus, where m is mass and ΔHfus is the enthalpy of fusion.

Heat of Vaporization

• The heat of vaporization can be expressed as q = m x ΔHvap, with ΔHvap being the enthalpy of vaporization.

Heat of Solution

• The heat of solution can be evaluated with qsoln = Cs (of solution) x m (of solution) x ΔT = -qrxn, indicating the relationship between heat gained/lost and reaction heat.

Heat of Reaction

• The heat of reaction (qrxn) is determined by qrxn = -Ccal x ΔT, where Ccal is the calorimeter's heat capacity and ΔT is the temperature change.

Test your understanding of thermodynamics in AP Chemistry with these flashcards. Each card covers essential formulas and concepts, including kinetic energy, internal energy changes, and the first law of thermodynamics. Perfect for quick reviews and exam preparation!