--%>
Assignment Help - homework help

F-centres

If a electron is present in place of anion in a crystal lattice, then it is termed as: (a) Frenkel defect  (b) Schottky defect  (c) Interstitial defects (d) F-centre

Answer: (d) When electrons are trapped in anion vacancies, these are called F-centres.

   Related Questions in Chemistry

  • Q : Explain the preparation of phenols. The

    The methods used for the preparation of phenols are given below:    From aryl sulphonic acids

    		•
  • Q : Infrared Adsorption The adsorption of

    The adsorption of infrared radiation by diatomic molecules increases the vibrational energy fo molecules and gives information about the force constant for the "spring" of the molecule.;The molecular motion that has the next larger energy level spacing aft

    		•
  • Q : Dipole moment direction for the methanol

    Briefly describe the dipole moment direction for the methanol?

    		•
  • Q : Number of mlecules in methane Can

    Can someone please help me in getting through this problem. The total number of molecules in 16 gm of methane will be: (i) 3.1 x 1023 (ii) 6.02 x 1023 (iii) 16/6.02 x 1023 (iv) 16/3.0 x 1023

    		•
  • Q : Quantum Mechanical Operators The

    The quantum mechanical methods, illustrated previously by the Schrödinger equation, are extended by the use of operators. Or, w

    		•
  • Q : Tetrahedral holes In zinc blende

    In zinc blende structure, zinc atom fill up:(a) All octahedral holes  (b) All tetrahedral holes  (c) Half number of octahedral holes  (d) Half number of tetrahedral holesAnswer: (d) In zinc blende (ZnS

    		•
  • Q : Calculating amount of Sodium hydroxide

    Choose the right answer from following. The amount of NaOH in gms in 250cm3 of a0.100M NaOH solution would be : (a) 4 gm (b) 2 gm (c) 1 gm (d) 2.5 gm

    		•
  • Q : Problem on equilibrium composition The

    The catalytic dehydrogenation of 1-butene to 1,3-butadiene, C4H8(g) = C4H6(g)+H2(g) is carried out at 900 K and 1 atm.

    Q : Thermodynamics I) Sulphur dioxide (SO2)

    I) Sulphur dioxide (SO2) with a volumetric flow rate 5000cm3/s at 1 bar and 1000C is mixed with a second SO2 stream flowing at 2500cm3/s at 2 bar and 200C. The process occurs at steady state. You may assume ideal gas behaviour. For SO2 take the heat capacity at constant pressure to be CP/R = 3.267

    		•
  • Q : Cations Chromium(III) hydroxide is

    Chromium(III) hydroxide is highly insoluble in distilled water but dissolves readily in either acidic or basic solution. Briefly explain why the compound can dissolve in acidic or in basic but not in neutral solution. Write appropriate equations to support your answer

    		•