Ask a Doubt
Request a call back

Join NOW to get access to exclusive study material for best results

CBSE Class 12-science Answered

calculate the avagadro number if iron crystallises as fcc and its density is 2.8g/cm^3 . if the volume of unit cell is 56.38 * 10^-24 cm^3/unit cell ( atomis mass = 56 )
Asked by Akshaya Parthasarathy | 02 Jul, 2011, 12:00: AM
answered-by-expert Expert Answer
1.Density= 2.8 g/cm3.
  As it crystallises in fcc lattice ,
  i.e.there are '8' Iron atoms at the corners and there contribution is 1/8.
      and 6 at 6 faces of the cube
     and atoms at the faces contribute=1/2.
    Therefore, total no. of Iron atoms per cube,(Z)=(8*1/8+6*1/2)=(1+3)=4 atoms.
 
Density=mass/volume
volume=(56.38*10-24)cm3/unit cell.
mass of single = Z*(56)/NA,  where NA=Avogadro's number.
Therefore, density*volume=Z*(55.84)/NA.
2.8*56.84=4*56/NA.
NA=4*56/2.8*56.84.
Answered by | 04 Jul, 2011, 11:10: AM

Concept Videos

Multiple Choice Questions Practice Test
Answered Unanswered My Questions My Answers
CBSE 12-science - Chemistry
law spin complex of d6 cation in an octahedral field will have the following energy
Asked by rasmimajhi07 | 21 Nov, 2023, 10:22: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 12-science - Chemistry
what do you understand by the space lattice and unit cell
Asked by pradeepkumar70258 | 04 Oct, 2023, 10:30: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 12-science - Chemistry
what is the efficiency power of Fcc unit cell
Asked by shreyasingh3652 | 28 May, 2022, 11:06: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 12-science - Chemistry
what is solid
Asked by harshul2019 | 25 May, 2022, 08:52: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 12-science - Chemistry
In diamond C atoms occupy FCC lattice points as well as alternate tetrahedral voids the edge length of unit of unit cell is 356.7pm.Calculate the closest distances between C atom and the fraction of total volume occupies by C atom.
Asked by sardaarjii2012 | 31 Oct, 2021, 09:05: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 12-science - Chemistry
metal crystallises in BCC structures atomic mass of the metal is 55.8g\mol calculate edge length of unit cell of the metal
Asked by karennavarpriya | 20 Aug, 2021, 01:53: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 12-science - Chemistry
In a FCC lattice , atoms A occupy the corner positions and atoms B occupy the face centre positions. If one atom of B is missing from one of the face centred points, calculate the formula of the compound
Asked by akash9322793205 | 12 Aug, 2021, 09:30: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 12-science - Chemistry
cation A occupies 2/3rd of all the octahedral voids while the anion B is found in all lattice points predict the formula of the ionic compound formed by them
Asked by shrinithishri2003 | 22 Jun, 2021, 12:09: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 12-science - Chemistry
which ionic compound shows both frenkle and schottky defect
Asked by apoorvaks26 | 10 May, 2021, 09:24: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 12-science - Chemistry
The unit cell of Na is bcc and its density is 0.97. What is the radius of a sodium atom if the molar mass of Na is 23?
Asked by arushidabhade | 17 Mar, 2021, 01:24: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
My Class Videos Tests ₹ Plans Ask a Doubt
Get Latest Study Material for Academic year 24-25 Click here
×