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EXERCISE ON CALCULATION OF SOLID STATE
1.
Cesium Bromide has the same structure as Cesium Chloride .Its density is 5000 kg m –3.Calculate the
length of the unit cell edge.
2.
In a crystal of potassium chloride, the internuclear distance is 0.314 nm, measured by x-ray analysis .It has
a face-centered cubic structure with a density of 2004 kg m-3.
(a) What is the number if formula unit in one of this unit cell?
(b) Calculate the volume occupied by a formula unit in this unit cell.
(c) From the density given, calculate the volume occupied by one mole of formula units of potassium
chloride.
(d) Determine a value of Avogadro constant from your results in (c) and (b).
3.
Consider the lattice structure of sodium chloride.
(a) X-ray diffraction method is used for determining lattice spacing in crystals .The Bragg ‘s equation is
basic to X-ray crystallography and shows a relationship between the angle of diffraction, wavelength
of X-ray and the spacing between atoms within the crystal, nλ ＝2a sinΘ.Explain why X-ray can
only be applied in this method .(The diameter of an atom is about 0.25 nm)
(b) If X-rays with λ＝0.1537 nm are diffracted by the top two planes of atoms in the sodium chloride
structure ,with a smallest angle of diffraction of 15.5°,what is the internuclear distance between
sodium ion and chloride ion?
(c) If this spacing is the same is all directions, what volume does a formula unit occupy?
(d) If the density of solid sodium chloride is measured as 2165 kgm-3, what is the volume of one mole
of a formula unit of sodium chloride?
(e) Calculate a value of Avogardro ‘s constant by using the results obtained from the above calculations.
4.
The density of solid cesium chloride is 3.97 x 10 +3.Its formula mass is 0.168 ㎏ mol-1and the
internuclear distance between cesium ion and a chloride ion in the crystal is 0.357 nm.
(a) Draw a diagram to show the unit cell of crystalline cesium chloride.
(b) What is the length of the unit cell edge?
(c) How many formula units contained in one unit cell of cesium chloride?
(d) Calculate the volume occupied by a formula unit in this unit cell.
(e) From the density given, calculate he volume occupied by one mole of ion pairs of cesium chloride.
(f) Calculate a value for the Avogadro constant.
5.
The figure shows the unit cell of calcium fluoride:
(1) What is the co-ordination number of calcium ion?
(2) Work out the unit cell contents and hence deduce the empirical formula of calcium fluoride.
6.
The following is a unit cell of an oxide of titanium:
(1) What is the co-ordination number of titanium?
(2) State the number of titanium ions and oxygen ions per unit. Explain your answer.
(3) Write the formula of the compound.
7.
Write the chemical formula for the followings:
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1.
Sodium carbonate
2.
Iron (III) sulphate
3.
Aluminum chloride
4.
Potassium dichromate
5.
Calcium nitrate
6.
Carbon monoxide
7.
Hydrogen chloride
8.
Aluminum oxide
9.
Zinc sulphate
10. Nitrogen trichloride
8.
Name the followings:
9.
KMnO4
Pb(OH)3
CH4
FeCl2
CuSO4
NH3
CCl4
Fe2O3
Mg (NO3) 2
10.
CO2
1.
2.
3.
4.
5.
6.
7.
8.