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An element has a face-centred cubic (fcc) structure with a cell edge of a. The distance between the centres of two nearest tetrahedral voids in the lattice is :

  • Option 1)

    \frac{a}{2}

  • Option 2)

    a

  • Option 3)

    \sqrt{2a}

  • Option 4)

    \frac{3}{2}a

  No. of atoms(z) for face centered unit cell - Lattice points: at corners and face centers of unit cell. For face centered cubic (FCC), z=4. - wherein     Relation between radius of constituent particle, r and edge length, a for face centered cubic unit cell -                                                    -       We know that, in fcc cell unit, the tetrahedral voids are located at...

              Consider the following table :

Gas           a/(k\: \: Pa \: \: dm^{6}\: \: mol^{-1})        b/(\: \: dm^{3}\: \: mol^{-1})

A                           642.32                                      0.05196

B                          155.21                                       0.04136

C                          431.91                                       0.05196

D                          155.21                                       0.4382

               a and b are van der Waals constants. The correct statement about the gases is :

  • Option 1)

    Gas C will occupy more volume than gas A;

    gas B will be more compressible than gas D

  • Option 2)

    Gas C will occupy lesser volume than gas A;

    gas B will be lesser compressible than gas D

  • Option 3)

    Gas C will occupy more volume than gas A;

    gas B will be lesser compressible than gas D

  • Option 4)

    Gas C will occupy lesser volume than gas A;

    gas B will be more compressible than gas D

In Vanderwaal's equation, a & b are constants      Here 'a' is defined as greater the value of 'a' , greater is the force of attraction & smaller is the volume. & ' b ' is defined the greater the value of ' b ' , higher will  be the effective volume & less will be the compressibility.   Gas 'C' will occupy more volume than Gas 'A' , Gas 'B' will be more compressible than Gas 'D'. option (1)...

The ratio of a number of atoms present in a simple cubic, body-centered cubic and face-centered cubic structure are, respectively:

 

  • Option 1)

    8 : 1 : 6

  • Option 2)

    1 : 2 : 4

  • Option 3)

    4 : 2 : 1

  • Option 4)

    4 : 2 : 3

 
  No. of atoms(z) for simple cubic unit cell - Lattice points: at corners For simple cubic (SC), z=1 - wherein       No. of atoms(z) for face centered unit cell - Lattice points: at corners and face centers of unit cell. For face centered cubic (FCC), z=4. - wherein       z for body centered unit cell - Lattice points: at corners and body center of unit cell. For body centered cubic (BCC),...

Points I,II and III in the following plot respectively correspond to 

\left ( V_{mp}: most probable velocity )

  • Option 1)

    V_{mp} \; of\; N_{2}\left ( 300\; K \right );V_{mp} \; of\; O_{2}\left ( 400\; K \right );V\; _{mp}\; of \; H_{2}\; \left ( 300K \right )

     

     

     

  • Option 2)

    V_{mp} \; of\; O_{2}\left ( 400\; K \right );V_{mp} \; of\; N_{2}\left ( 300\; K \right );V\; _{mp}\; of \; H_{2}\; \left ( 300K \right )

  • Option 3)

    V_{mp} \; of\; N_{2}\left ( 300\; K \right );V_{mp} \; of\; H_{2}\left ( 300\; K \right );V\; _{mp}\; of \; O_{2}\; \left ( 400K \right )

  • Option 4)

     V_{mp} \; of\; H_{2}\left ( 300\; K \right );V_{mp} \; of\; N_{2}\left ( 300\; K \right );V\; _{mp}\; of \; O_{2}\; \left ( 400K \right )

For  Option 1)      Option 2)Option 3)Option 4) 

At a given temperature T , gases Ne, Ar , Xe and Kr are found to deviate from ideal gas behaviour . Their equation of state is given as p=\frac{RT}{V-b}  at T  . Here , b is the van der Waals constant . Which gas will exhibit steepest increase in the plot of Z ( compression factor ) Vs p ?

  • Option 1)

    Xe

  • Option 2)

    Kr

  • Option 3)

    Ne

  • Option 4)

    Ar

  Compressibility Factor - used to find deviation of a gas from ideal behaviour -     Compressibility Factor - -     Compressibility Factor - For ideal gas Z=1 -     Compressibility Factor - at  low pressures, all gases have Z less than 1. -     Compressibility Factor - at very high pressure, all gases have Z greater than 1. -     Compressibility Factor - for hydrogen and helium, Z is ...

Consider the bcc unit cells of the solids 1 and 2 with the position of atoms as shown below. The radius of atoms B is twice that of atom A. The unit cell edge length is 50% more in solid 2 than in 1. What is the approximate packing efficiency in solid 2?

  • Option 1)

    45%

  • Option 2)

    75%

  • Option 3)

    90%

  • Option 4)

    65%

  length of body diagonal =                                        =                                        =                                                                                                                             = 91.27%=90%                                         Option 1)45%Option 2)75%Option 3)90%Option 4)65%

Consider the van der Waals constants, a and b, for the following gases.

                \; \; \; Gas\; \; \; \; \; \; \; \; \; \;\; \; \; Ar\; \; Ne \; \; Kr \; \; Xe

a/\left ( atm\; dm^{6}mol^{-2} \right ) 1.3 \; \; 0.2\; \; 5.1\; \; 4.1

b/\left ( 10^{-2}dm^{3}mol^{-1} \right )\; 3.2\; \; 1.7\; \; 1.0\; \; 5.0

 Which gas is expected to have the highest critical temperature?

  • Option 1)

    Kr

  • Option 2)

    Ne

  • Option 3)

    Xe

  • Option 4)

    Ar

The highest critical temperature                                                              (Maximum)                                   is the answerOption 1)Option 2)Option 3)Option 4)
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@santhosh 40 give that table 4) is correct option  Types of Colloid Dispersed Material Gas (bubbles) Dispersed in Gas Not possible Dispersed in Liquid Foams: soda pop; whipped cream; beaten egg whites Fogs: mist; Emulsions: milk; Liquid (droplets) clouds; hair sprays blood; mayonnaise Solid (grains) Smokes: dust; industrial smoke Sols and gels: gelatin;...


How many nearest Na+ ions and Cl- ions surrounds
chloride ion in Rock salt structure respectively?
(4) 6,12
 

States_of_matter.jpg

The radius of the largest sphere which fits properly at the centre of the edge of a body centred cubic unit cell is : (Edge length is represented by 'a' )

  • Option 1)

    0.134 a

  • Option 2)

    0.047 a

  • Option 3)

    0.027 a

  • Option 4)

    0.067 a

  Relation between radius of constituent particle, R and edge length, a for body centered cubic unit cell - -  Option 1)0.134 aOption 2)0.047 aOption 3)0.027 aOption 4)0.067 a

A solid having density of 9\times 10^{3} kg m^{-3} forms face centred cubic crystals of edge length 200\sqrt{2} pm . What is the molar mass of the solid ?

[ Avogadro constant \cong 6\times 10^{23} mol ^{-1}, \pi \cong 3]

  • Option 1)

     0.0216 kg mol^{-1}

  • Option 2)

    0.0305\: kg\: mol^{-1}

  • Option 3)

    0.0432kg \: \: mol^{-1}

  • Option 4)

     0.4320\: kg \: mol^{-1}

  Density of cubic unit cell -   - wherein Where, d = density of crystal z = no. of effective constituent particles in one unit cell M = molecular weight a = edge length of unit cell No = 6.022*1023 As we learned  Option 1) Option 2)Option 3)Option 4) 

Acompound of formula A_{2}B_{3}  has  the hcp lattice Which atom forms the hcp lattice and what fraction of tetra hedral voids is occupied by the other atoms:

  • Option 1)

    hcp lattice -B ,\frac{2}{3}  tetrahedral voids

     

  • Option 2)

    hcp lattice -A , \frac{1}{3} tetrahedral voids -B

  • Option 3)

    hcp lattice -B , \frac{1}{3}  Tetrahedral voids -A

  • Option 4)

    hcp lattice - A ,\frac{2}{3} Tetrahedral voids -B

  Tetrahedral Voids - Voids form by touching 4 spheres , 3 in the same plane and one in lower or upper plane is known as tetrahedral void.   - wherein r = radius of void R = radius of atom       Voids - Voids are empty spaces in a unit cell. They are of four types: triangular, tetrahedral, octahedral, cubic. -    Option 1)hcp lattice -B ,  tetrahedral voids  Option 2)hcp lattice -A , ...

An open vessel at 270 C is heated until two fifth of the air (assumed as an ideal gas ) in it has escaped from the vessel. Assuming that the volume of  the vessel remains constant, the temperature at which the vessel has been heated is :

  • Option 1)

    750 K

  • Option 2)

    750 oC

     

  • Option 3)

    500 oC

  • Option 4)

    500 K 

  Ideal Gas Law in terms of density - - wherein where d - density of gas P - Pressure R - Gas Constant T - Temperature M - Molar Mass       Saturated Vapour Pressure - When equilibrium is attained between vapor and liquid kept in a partially filled beaker , the vapour pressure at that temperature is called saturated vapor pressure.   As we have learned in gaseous state we know air escaped for...

Which premitive unit cell has unequal edge lengths (a\neq b\neq c) and all axial angles different from 90^{0}?

  • Option 1)

    Triclinic 

  • Option 2)

    Hexagonal

  • Option 3)

    Monoclinic

  • Option 4)

    Tetragonal

  Unit cell - Smallest repeating unit of crystal lattice. -     Relation between radius of constituent particle, R and edge length, a for simple cubic unit cell - -   @tr  As we have learnt in Triclinic unit cell. In triclinc unit cell        Option 1)Triclinic Option 2)HexagonalOption 3)MonoclinicOption 4)Tetragonal

The volume of gas A is twice than that of gas B. The compressibility factor of gas A is thrice than that of gas B at same temperature. The pressures of the gases for equal number of moles are :

  • Option 1)

    2P_{A}=3P_{B}

  • Option 2)

    3P_{A}=2P_{B}

  • Option 3)

    P_{A}=2P_{B}

  • Option 4)

    P_{A}=3P_{B}

@com    Compressibility Factor - -     Compressibility Factor - at  low pressures, all gases have Z less than 1. - As we  know from ideal gas equation atconstant T and mol THere for    Option 1)Option 2)Option 3)Option 4)

At 100^{\circ}C , copper (Cu) has FCC unit cell structure with cell edge length of x\AA. . What is the approximate density of

Cu(in\; gcm^{-3})  at this temperature ?

[ Atomic Mass of Cu = 63.55 u]

  • Option 1)

    \frac{105}{x^{3}}

  • Option 2)

    \frac{211}{x^{3}}

  • Option 3)

    \frac{205}{x^{3}}

     

  • Option 4)

    \frac{422}{x^{3}}

  Density of cubic unit cell -   - wherein Where, d = density of crystal z = no. of effective constituent particles in one unit cell M = molecular weight a = edge length of unit cell No = 6.022*1023 The FCC unit cell has Z=4  Option 1)Option 2)Option 3)  Option 4)

0.5 moles of gas A and x moles of gas B exert a pressure of 200 Pa in a container of volume 10m3at 1000 K .Given R is the gas constant in JK-1 mol-1 , x is:

  • Option 1)

    \frac{2R}{4+R}

     

     

  • Option 2)

    \frac{2R}{4-R}

  • Option 3)

    \frac{4+R}{2R}

  • Option 4)

    \frac{4-R}{2R}

  Partial Pressure of a gas in gaseous mixture - Partial Pressure = (Total Pressure of Mixture)  (mole fraction of gas)     Critical Volume - volume of gas-liquid equilibrium at critical pressure and temperature - As we know the formula here 20010=(0.5x) R1000 2=(0.5+x)R the correct option is       -    Option 1)    Option 2)Option 3)Option 4)

Question

At 100oC a gas has 1 atm pressure and 10 L volume . Its volume at NTP would be -

A.

10 L

B.

Less than 10 L

C.

More than 10 L

D.

None of these

    ,      i.e less than 10L     Charles’s Law - At constant pressure and moles, volume is directly proportional to temperature of gas. - wherein            Option 2) Less than 10 L This is correct
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