Home
Class 12
CHEMISTRY
The mole fraction of Schottky defect and...

The mole fraction of Schottky defect and Frenkel defects, in `NaCl` crystal at `1000K` are respectively. If energy required to produce these defects are `2eV` and `3eV` respectively.
`(1eV=1.6xx10^(-19)J` and `k=1.38xx10^(-23)JK^(-1))`

A

`3.62xx10^(-7)` and `6.32xx10^(-9))`

B

`9.17xx10^(-6)` and `3.924xx10^(-8)`

C

`2.86xx10^(-5)` and `5.38xx10^(-8)`

D

`5.40xx10^(-8)` and `8.31xx10^(-9)`

Text Solution

Verified by Experts

The correct Answer is:
b
Let the no. of Schottky defect be `n` in an ioinic crystal having `N` ions.
`(n)/(N)=e^(-E//2kT)`
`e^(((2xx1.6xx10^(-19))/(2xx1.38xx10^(-23)xx1000)))`
`e^(-11.6)=9.17xx10^(-6)`
Suppose the no. of Frenkel defects be `n` in an ionic crystal having `N` ions and interstitial space `N_((i))`.
`n=sqrt(NxxN_((i)))e^(-E//2kT)`
`( :' N_((i))=2N)`
`:. n=sqrt(2)Ne^(-E//2kT)`
`:. (n)/(N)=sqrt(2)e^(((3xx1.6xx10^(-19))/(2xx1.38xx10^(-23)xx1000)))`
or `=sqrt(2)e^(-17.4)=3.924xx10^(-8)`
Promotional Banner

Topper's Solved these Questions

  • SOLID STATE

    P BAHADUR|Exercise Exercise 9|1 Videos

  • MOCK TEST PAPER

    P BAHADUR|Exercise Exercise|92 Videos

  • SURFACE CHEMISTRY

    P BAHADUR|Exercise Exercise 5|1 Videos

Similar Questions

Explore conceptually related problems

The number of Schottky defects (n) present in an ionic compound containing N ions at temperature T is given by n = Ne^(-E//2KT) , where E is the energy required to create n Schottky defects and K is the Boltzmann constant, If the mole fraction of Schottky defect in NaCl crystal at 2900 K is X , then calculate -ln(x) , Given: DeltaH of Schottky defect = 2 eV and K = 1.38 xx 10^(-23) J K^(-1) 1 eV = 1.608 xx 10^(-19) J

What fraction (n/N) of the lattice sites are vacant at 298 K for a crystal in which the energy required to make a defect is 1 eV. (1 eV = 1.602 xx 10^(-19) J)

Calculate the average kinetic energy of hydrogen molecule at 0^(@)C . Given k_(B)=1.38xx10^(-23)JK^(-1) .

Work functions of copper and cesium are 4.5 eV and 1.9 eV, respectively. What are the corresponding threshold frequencies for these metals ?

The de Broglie wavelength of an electron in a metal at 27^(@)C is ("Given"m_(e)=9.1xx10^(-31)kg,k_(B)=1.38xx10^(-23)JK^(-1))

Calculate the average kinetic energy of neon molecule at 27^(@)C . Given k_(B)=1.38xx10^(-23)JK^(-1)