Chemical potential

GCWUS

1. Chemical potential presented to: Dr. Shazia Presented by: Maria Yasmin Roll no. 7

2. introduction Energy that can be absorbed or released due to a change of the particle number of the given species. Also known as partial molar free energy. μ a = ∆G/∆ n a Josiah Willard Gibbs. Chemical potential of a chemical substance, μ, can be simply defined as the chemical energy possessed by 1 mol of the substance . Σμ i ·= ∆ G / ∆ n i at constant T, P

3. IMPORTANCE OF CHEMICAL POTENTIAL …1 Raoult's law Mole Fraction x w + x s = 1 x w = 1 - x s The change in chemical potential with pressure

4. Continue… Using equation 1 By putting the value of ‘ X w ’ Π V m = -RT ln (1-x s ) When x s is low, the following approximation is valid ln (1 - x s ) = - x s Π V m = x s RT At low x s , x s = n s / n w

5. Continue… Given the volume of water (V ), V = n w ˣ V m The molar concentration of the solute is c s = n s /V = x s n w / n w V m   = x s / V m Put this value in eq. 4                                     Π = c s RT Eq. 4 is Π V m = x s RT Π /c = RT   Π /c = RT/ M n

6. Physical significance The tendency of a substance to react with other substances, to transform into another state, to redistribute in space, The magnitude of this tendency, meaning the numerical value of µ is determined by the nature of the substance,. A reaction, transformation, redistribution, etc. can only proceed voluntarily if the tendency for the process is more pronounced in the initial state than in the final state.

7. Chemical Potential Energy and life It is the energy stored up in substances due to their chemical bonds. It is energy that is stored in chemicals. One example of how this plays a part in real life is through plants. The plants make energy with chemical potential energy by the process of photosynthesis. Other organisms eat the plants to get energy and so on. Energy is passed from one organism to another. This is how chemical potential energy works in the environment. Another common example is the energy stored in gasoline. When the car is turned on, the chemical energy in the gas is converted into mechanical energy to move the car. The law of conservation of energy says energy cannot be created or destroyed. It can only be changed from one form into another.

8. Thank you .