Which among the following are true about the activation barrier of homogeneous and heterogeneous nucleation?

G(hom) is always a constant but G(het) varies with temperature

15 + Mcqs in Solidification Nucleation in Pure Metal Page 1 McqOptions

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Which among the following are true about the activation barrier of homogeneous and heterogeneous nucleation?

In some metallic systems the liquid can be rapidly cooled to temperatures below the so-called glass transition temperature without the formation of crystalline solid.

Value of shape factor of heterogeneous nucleation if is given as 60 ?

Calculate the value of Gv if the interfacial energy is given as 3kJ/mm2Kmol and the critical radius is given as 1.5mm?

If the liquid contains x atoms per unit volume, calculate the number of clusters that have reached the critical size (Y), if the temperature is taken at T (K) and the critical value of change in free energy at homogenous nucleation is given as G ?

Calculate the critical radius, if the interface energy is given as 3kJ/m2Kmol and the undercooling is given as 300K ( T)? (Assume the latent heat of fusion per unit volume as L and the melting point temperature (Tm) as 150K).

Calculate the G (critical) if the Gv and values are given as kJ/m3Kmol and 3kJ/m2Kmol respectively? (Homogenous nucleation)

Calculate the critical radius if the Gv and values are given as 5 kJ/m3Kmol and 2.5 kJ/m2Kmol respectively? (Homogeneous nucleation)

For a given undercooling there is a certain radius r*, which is associated with a maximum excess free energy. If r< r* the system can lower its free energy by_____

Calculate the volume free energy associated with homogenous nucleation of sphere if the radius of the sphere is given as 5m and the Gv is given as (3/ ) kJ/m3Kmol?

The free energy change associated with homogeneous nucleation of a sphere (assume the radius as 5m) has an interfacial energy term and a volume free energy. Calculate the value of the interfacial term if the interfacial energy is given as (1/ ) kJ/m2Kmol?

Let s take the equilibrium melting temperature of a fluid A as Tm and which is cooled below its equilibrium melting temperature (Tm) then there is always possibility of a driving force F for solidification and it might be expected that the liquid phase of A would spontaneously solidify.

If the latent heat of fusion is given as L and the melting temperature of that substance is given as x. For an undercooling T, the change in free energy is given as _________

If the volume of the solid sphere and the volume of the liquid is given as V1 and V2 respectively, G1 and G2 are the free energies per unit volume of solid and liquid respectively. The free energy of the system without any solid present is given by_______

Calculate the value of Gv if the interfacial energy is given as 3kJ/mm²Kmol and the critical radius is given as 1.5mm?

Calculate the critical radius, if the interface energy is given as 3kJ/m²Kmol and the undercooling is given as 300K ( T)? (Assume the latent heat of fusion per unit volume as L and the melting point temperature (Tm) as 150K).

Calculate the G (critical) if the Gv and values are given as kJ/m³Kmol and 3kJ/m²Kmol respectively? (Homogenous nucleation)

Calculate the critical radius if the Gv and values are given as 5 kJ/m³Kmol and 2.5 kJ/m²Kmol respectively? (Homogeneous nucleation)

For a given undercooling there is a certain radius r, which is associated with a maximum excess free energy. If r< r the system can lower its free energy by_____

Calculate the volume free energy associated with homogenous nucleation of sphere if the radius of the sphere is given as 5m and the Gv is given as (3/ ) kJ/m³Kmol?

The free energy change associated with homogeneous nucleation of a sphere (assume the radius as 5m) has an interfacial energy term and a volume free energy. Calculate the value of the interfacial term if the interfacial energy is given as (1/ ) kJ/m²Kmol?