Introduction to Thermodynamics, Cheat Sheet of Energy and Environment

Download Introduction to Thermodynamics and more Cheat Sheet Energy and Environment in PDF only on Docsity! 1 Laws of Thermodynamics:  Zeroth Law: If two systems are each in thermal equilibrium with a third, they are in thermal equilibrium with each other.  First Law: Energy cannot be created or destroyed in an isolated system; it can only change forms. ∆𝑈 = 𝑄 −𝑊 ΔU is the change in internal energy. Q is heat added to the system. W is work done by the system.  Second Law: In any energy transfer or transformation, the total entropy of a closed system will always increase over time. ∆𝑆 = 𝑄 𝑇 ΔS is the change in entropy. Q is heat added to the system. T is temperature in Kelvin.  Third Law: As the temperature of a system approaches absolute zero (0 K), the entropy of the system approaches a minimum value. Concepts:  Temperature: Measure of the average kinetic energy of particles in a substance.  Heat: Energy transferred between substances due to a temperature difference.  Work: Energy transfer caused by a force acting over a distance.  Thermal Equilibrium: When two objects are at the same temperature and no heat flows between them when they're in contact. Processes:  Isobaric: Constant pressure.  Isochoric (isovolumetric): Constant volume.  Isothermal: Constant temperature.  Adiabatic: No heat transfer. Thermodynamic Systems:  Open System: Allows both energy and matter exchange with its surroundings.  Closed System: Allows only energy exchange with its surroundings. Basics of Thermodynamics 2  Isolated System: Allows neither matter nor energy exchange with its surroundings. Carnot Cycle: The most efficient theoretical heat engine cycle, consisting of four reversible processes: isothermal expansion, adiabatic expansion, isothermal compression, adiabatic compression.  Carnot Efficiency: 𝜂 = 1 − 𝑇𝑐 𝑇𝐻 𝜂 : is the efficiency of a heat engine. 𝑇𝑐: is the absolute temperature of the cold reservoir. 𝑇𝐻: is the absolute temperature of the hot reservoir. Ideal Gas: PV = nRT P is pressure. V is volume. n is the number of moles. R is the ideal gas constant. T is temperature in Kelvin. Van der Waals Equation (Non-Ideal Gases): (𝑃 + 𝑎𝑛2 𝑉2 ) (𝑉 − 𝑛𝑏) = 𝑛𝑅𝑇 P is pressure. V is volume. n is the number of moles. a and b are constants specific to the gas. Work W: For an ideal gas undergoing reversible isothermal expansion or compression: 𝑊 = −𝑃. ∆𝑉 W is work done. P is pressure. ΔV is change in volume. Heat Transfer equation: The amount of heat (Q) transferred during a process is determined by the formula: 𝑄 = 𝑚𝑐∆𝑇 Q is heat transferred. m is the mass of the substance. c is the specific heat capacity of the substance. ΔT is the change in temperature. In phase changes: T=cst 𝑄 = 𝑚𝐿 Q is heat transferred. m is the mass of the substance. L is the latent heat of the substance