Home
Class 12
CHEMISTRY
Sodium chloride crystallizes in face-cen...

Sodium chloride crystallizes in face-centred cubic (f.c.c.) structure. Its density is 2.165 g `cm^(-3)`. If the distance between `Na^+` and its nearest `Cl^(-)` ions is 281 pm, find out the Avogadro's number (Na = 23 g `"mol"^(-), Cl = 35.5 g "mol"^(-)`).

Text Solution

Verified by Experts

For a cubic unit cell,
`d=(ZM)/(a^3 10^(-30)N_A) g cm^(-3)` or `N_A=(ZM)/(10^(-30)d a^3)`
When .a. is in pm.
Where M=Molar mass of NaCl = 23 + 35.5 = 58.5 g `mol^(-)`
`N_A`=Avogadro.s number = ?
d= density = 2.165 g `cm^(-3)`
Z= number of atoms per unit cell = 4 (f.c.c.)
a=edge length of the unit cell in pm.
For NaCl type crystal, edge length (a) = `2 xx "interionic distance"` = 2 (281) = 562 pm
`:. N_A=(4 xx 58.5 g mol^(-))/(10^(-30) xx 2.165 g cm^(-3) xx (562)^3 cm^3)`
`=(234.0 g mol^(-1))/(8 xx 22188041 xx 10^(-30) xx 2.165 g) = 6.09 xx 10^(23) mol^(-)`
Promotional Banner

Topper's Solved these Questions

  • SOLID STATE

    ICSE|Exercise WORKED OUT EXAMPLE(Type IV. Calculation of Atomic Mass and Number of Atoms in a Given Mass.)|2 Videos

  • SOLID STATE

    ICSE|Exercise WORKED OUT EXAMPLE(Type V. Determination of the Nature of the unit cell and Number of Atoms per unit cell)|3 Videos

  • SOLID STATE

    ICSE|Exercise WORKED OUT EXAMPLE(Type II. Calculation of Edge length, Interionic distances and volume of unit cell from Density.)|4 Videos

  • SELF ASSESSMENT PAPER-8

    ICSE|Exercise QUESTIONS|11 Videos

  • SOLUTIONS

    ICSE|Exercise MULTIPLE CHOICE QUESTIONS (Assertion and Reason based questions)|10 Videos

Similar Questions

Explore conceptually related problems

CsCl has cubic structure. Its density is 3.99 g cm^(-3) . What is the distance between Cs^(o+) and Cl^(Θ) ions? (Atomic mass of Cs = 133 )

A compound CuCl has face - centred cubic structure. Its density is 3.4g cm^(-3) . What is the length of unit cell ?

A compound CuCl has face - centred cubic structure. Its density is 3.4g cm^(-3) . What is the length of unit cell ?

Niobium crystallizes in body-centred cubic structure. If the density is 8.55 g cm^(-3) , calculate the atomic radius of niobium using its atomic mass 93 u .

Niobium crystallizes in body-centred cubic structure. If the density is 8.55 g cm^(-3) , calculate the atomic radius of niobium using its atomic mass 93 u .

The distance between Na^+ and Cl^- ions in NaCl with a density 3.165 g cm^(-3) is

Potassium fluoride (KF) has NaCl structure . Its density is 2.48g cm^(-3) and its molar mass is 58g mol^(-1) . Compute the distance between K^(+) and F^(-) ions in KF .

The element chromium crystallises in a body centred cubic lattice whose density is 7.20g//cm^(3) . The length of the edge of the unit cell is 288.4 pm. Calculate Avogadro's number (Atomic mas of Cr = 52).

Chromium crystallizes in a body centred cubic lattice, whose density is 7.20 g//cm^3 . The length of the edge of unit cell is 288.4 pm. Calculate Avogadro's number. (Atomic mass of chromium=52)

What is the volume of a face centred cubic unit cell, when its density is 2.0 g cm^(-3) and the molar mass of the substance is 60.23 g mol^(-1) ?

ICSE-SOLID STATE-WORKED OUT EXAMPLE(Type III. Calculation of Avogadro.s Number)
  1. Sodium chloride crystallizes in face-centred cubic (f.c.c.) structure....

    Text Solution

    |