* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download New Microsoft Office Word Document
State of matter wikipedia , lookup
Entropy in thermodynamics and information theory wikipedia , lookup
R-value (insulation) wikipedia , lookup
Black-body radiation wikipedia , lookup
Countercurrent exchange wikipedia , lookup
Equipartition theorem wikipedia , lookup
Calorimetry wikipedia , lookup
Heat capacity wikipedia , lookup
Thermoregulation wikipedia , lookup
Thermal radiation wikipedia , lookup
Conservation of energy wikipedia , lookup
Equation of state wikipedia , lookup
Heat transfer wikipedia , lookup
Heat equation wikipedia , lookup
Temperature wikipedia , lookup
Extremal principles in non-equilibrium thermodynamics wikipedia , lookup
Internal energy wikipedia , lookup
Non-equilibrium thermodynamics wikipedia , lookup
Thermal conduction wikipedia , lookup
First law of thermodynamics wikipedia , lookup
Heat transfer physics wikipedia , lookup
Gibbs free energy wikipedia , lookup
Chemical equilibrium wikipedia , lookup
Chemical thermodynamics wikipedia , lookup
Adiabatic process wikipedia , lookup
Second law of thermodynamics wikipedia , lookup
Thermodynamics System:- Observed part of universe State of the system:- the existence of system with its respective microscopic and macroscopic properties Surrounding:- Part of universe apart from system Universe:- System along with all the surroundings Boundary:- Walls that separate System from Surroundings Equilibrium:- A state of dynamics wherein all observable properties are constant Thermodynamic Equilibrium:- A system in which all macroscopic properties do not undergo any change with time Thermal Equilibrium:- If there is no heat exchange from one portion of the system to the another portion of the system, the system is said to be in Thermal Equilibrium Mechanical Equilibrium:- If no work is done by one part of the system on other part of the system, it is termed as Mechanical Equilibrium Chemical Equilibrium:- If the rate of forward reaction equals the rate of backward reaction in the reversible conversion of some reactants to products in a closed container it is called Chemical Equilibrium Types of System:- System Open System Can exchange both mass and heat with surrounding Example:- a rection proceeding in a lid less container Closed System Can only exchange heat with the surrounding Example:- a reaction proceeding in a container with a lid Isolated System Can exchange neither mass nor heat with the surrounding Example:- a reaaction proceeding in a closed container with insulated walls, AThermos flask Properties of a system:- Intensive Properties • Does not change with amount or quantity • E.g:Temperature, Pressure Functions of a system:- Extensive Properties • Change with amount or quantity • E.g.:- Mass , Volume State Function Path Function Independent of the path followed from initial to final state of the system Depends on the path followed from initial to final state of the system E.g.:- ∆H, ∆U, ∆G (Change in enthalpy, internal energy, Gibb's free energy E.g:- work done, heat Types of thermodynamic processes:- Thermodynami c Process Isothermal Isochoric Adiabatic Isobaric Cyclic Reversible Irreversible ∆T= 0 ∆V= 0 ∆q= 0 TVγ-1 is constant ∆P= 0 ∆U= 0 Equilibrium can be achieved Equilibrium can not be achieved Laws of thermodynamics (statements):- ZEROTH LAW If two systems are in equilibrium with a same system externally then they are in equilibrium with each other too. FIRST LAW Energy can neither be created nor be destroyed, it can only be transformed into varius forms. SECOND LAW A reversible chemical reaction can only be reversed by introduction of an external agency THIRD LAW The entropy of a crystalline solid at absolute temperature(0K) is zero. Laws of thermodynamics (mathematical expression) Zeroth Law • A↔B↔C First Law • ∆U=∆q+∆W Second Law • at 0K, ∆S=0 Third Law • ∆S=2.303∫CPlog dT Internal Energy (U):- Sum total of all the energies of all molecules in a system. Internal energy cannot be determined rather the change in internal energy (∆U) can be determined. ∆U is negative for exothermic reaction ∆U is positive for endothermic reaction Internal energy depends on pressure, temperature, volume and quantity Work (W):- A form of energy. It can be defined as the product of volume and difference between pressure of system and surroundingoccurs in a gaseous matter. It is a path function Expression for various Thermodynamic Work :Irreversible, Isothermal work done and at constant pressure WPV=-Pext.∆V Reversible, Isothermal work done Wrev=-2.303 nRTlog(V2/V1) Reversible adiabatic work done:Wrev= Nr(T2-T1)/γ-1 Irreversible adiabatic work done Wirrev=-Pext.R{(P1T2-P2T1)/P1P2} SPECIAL POINT:Reversible work done is always greater than Irreversible work done Work done and heat are seen only at the boundary of system and surrounding at the time of change of state. Heat Capacity (q):- Amount of heat needed to increase the temperature of the system by 1̊C Molar heat capacity (q/n):- Heat capacity for one mole of matter Specific heat capacity (C or q/m):- Heat capacity for one gram of matter Molar heat capacity at constant pressure= CP = 5/2R Molar heat capacity at constant volume= CV = 3/2R CP – CV = R Poisson’s Ratio (γ) = CP/CV Atomicity of the gas Monoatomic Diatomic Triatomic Value of γ 1.66 1.40 1.33 Enthalpy (H):- sum of internal energy and stored energy of a system It is a state function and an extensive property H=U+PV ∆H=∆U+P∆V ∆H=U+∆nRT ∆H is positive for endothermic reactions ∆H is negative for exothermic reactions Enthalpy depends on the state of the system, allotropic forms of matter, composition of system, amount of reactants and temperature too Entropy (S):- Degree of randomness S=qrev/T ∆S= n.CV.ln(T2/T1)+n.R.ln(V2/V1) Gibb’s free energy (G):- It is defined as the difference of enthalpy and product of temperature with entropy. G=H-TS ∆G=∆H- T∆S ∆G = 0 at equilibrium ∆G = ∆G̊ + R.T.lnK At eqm, ∆G= -2.303.R.T.logK ∆G̊ = -nFE̊cell (for electrochemical cells) SIGN CONVENTIONS AND SPONTANIETY OF A REACTION Serial no. ∆H ∆S ∆G=∆H-T∆S 1 2 Negative Positive Positive Negative Negative Positive 3 Positive Positive 4 Negative Negative Low T, Positive High T, Negative Low T, Negative High T, Positive SOME OTHER LAWS Lavoisier Laplace Law A → B (H= ∆H1) B→A (H=-∆H2) Hess’s Law A→B (H=∆H1) A → C (H=∆H2) → D (H=∆H3) → B (H=∆H4) ∆H1 = ∆H2 + ∆H3 + ∆H4 Trouton’s Law Reaction type Spontaneous Non spontaneous Non spontaneous Spontaneous Spontaneous Non spontaneous ∆HVap/Tboiling = 88J/mol/K Dulong Petit Law C*M = 6.4 cal ̊C/mol Kirchoff’s Equation ∆CP = (∆H2 - ∆H2)/(T2 – T1) ∆CV = (∆U2 - ∆U2)/(T2 – T1) Clausius Clapeyron Equation -2.303 log(P2/P1) = ∆HVap/R{(T2 – T1)/T1T2} Joule Thomson Effect:Adiabatic expansion of a gas from high pressure to low pressure causes cooling of the gas Joule Thomson coefficient (µ) :- dT/dP SPECIAL POINT:Ideal gas expansion in vacuum witness no Joule Thomson effect When the temperature goes beyond Inversion Temperature, Joule Thomson coefficient is zero. Inversion Temperature (Ti) = 2a/Rb