Posts

Showing posts with the label Chemical potential and fugacity

Depression in Freezing point and Elevation in Boiling point

-
Image
Depression in Freezing Point: Depression in freezing point means freezing point of solution is always less than that of its pure solvent due to lowering of vapour pressure of solution. Depression in freezing point have the formula as given below, ∆T f = i × K f × m                                       eq.. (1) K f = cryoscopic constant This equation tells us that depression of freezing point depends only on   molality of solutions, so it is a colligative property. m= 1000W 2 /W 1 ×M 2                           putting the value of molality in we get          ∆T f   = i × K f × 1000W 2 /W 1 ×M 2        ...
Post a Comment
Read more

Fugacity and Activity in thermodynamics

-
Image
  Fugacity and Activity in Thermodynamics Fugacity and Chemical Potential How to determine fugacity of a gas? Fugacity and Activity: G.N. Lewis in 1901 introduced the concept of fugacity to explain the actual behavior of real gases in chemical equilibrium at high pressures. It is mainly employed in connection with gases mixture but the introductory treatment is restricted to pure gases. Fugacity indicates the escaping tendency of a component or a substance. High gas pressure indicates the tendency of gas molecules to escape outside the container. Similarly high fugacity indicates a greater tendency of a component or a substance to escape, dissolve or intermix. Fugacity may be explained as a substitute for pressure to explain the behavior of real gases and the activity may be defined as the substitute for the concentration to explain the behavior of a non- ideal or real solution. Mathematically, fugacity (f) is defined as        ...
Post a Comment
Read more

Popular posts from this blog

Balancing Redox Reactions by Ion-Electron method(part1)

-
Image
  How to balance redox reactions? How can we balance redox reactions by Ion-Electron method? Balancing redox reactions: The balancing of redox equations by the loss and gain of electrons, usually involves quite a few ions, which do not undergo change in valence and which are not necessary for the process of balancing. The ion –electron method eliminates a unnecessary ions and retains only those, which are essential. Following are the general rules for balancing redox equations by ion- electron method. 1.    Assign oxidation states to determine species being oxidized and reduced, and write the half reactions. 2.    Balance each half reaction. a.    Balance the atoms being oxidized or reduced. b.    Balance oxidation number by adding electrons. c.    Balance the other elements that are present, for example S with SO 4 2- or Cl with Cl 1- . d.    Balance oxygen atoms by adding H 2 O. e.    Balan...
Read more

Paramagnetic, Diamagnetic, Ferromagnetic, Antiferromagnetic and Ferrimagnetic behavior of substances

-
Image
What is Paramagnetic, Diamagnetic, Ferromagnetic, Antiferromagnetic and Ferrimagnetic behavior of substances? What is the effect of temperature on these properties? Paramagnetic substances: These substances are attracted by the magnetic field and have unpaired electrons. These lose magnetism in the absence of magnetic field. Some examples of paramagnetic substances are transition metals like Cr, Mn, Co, Fe and metal oxides like CuO,VO 2 . Diamagnetic substances: These substances are weakly repelled by magnetic field and have no unpaired electrons. Some examples of diamagnetic substances are H 2 O, benzene, NaCl, TiO 2 . Ferromagnetic substances: Such substances are strongly attracted by magnetic field. In the absence of magnetic field magnetic field these substances have magnetic domains randomly oriented in such a way that their overall magnetic moment gets cancelled. But in the presence of magnetic field they are oriented in such a way that they together produce a str...
Read more

Slater's Rule

-
Image
         What is Slater's Rule and its significance? How to calculate value of σ  and Zeff using Slater' Rule: Slater's Rule : Slater’s rules are a set of empirical guidelines used to calculate the shielding constant (σ) and the effective nuclear charge (Zeff) experienced by an electron in a multi-electron atom. They were introduced by John C. Slater to simplify the complex quantum mechanical interactions between electrons. These rules estimate how much the inner electrons reduce the attractive force of the nucleus on outer electrons. Mathematically:                              Zeff=Z−S where: Z = atomic number (total nuclear charge)             S = shielding constant (calculated using Slater’s rules Significance of Slater's Rule: To quanti...
Read more