Advertisements
Advertisements
Question
Copper crystallises into a fcc lattice with edge length 3.61 × 10−8 cm. Show that the calculated density is in agreement with its measured value of 8.92 g cm−3.
Advertisements
Solution
Given: For fcc lattice, Z = 1 + 3 = 4 atoms
Edge length, a = 3.61 × 10−8 cm,
Atomic mass of Cu = 63.55 gm mo1−1
Avogadro’s number (NA) = 6.022 × 1023
To find: Density of Cu = ?
Formula: `rho = (Z xx M)/(a^3 xx N_A)`
= `(4 xx 63.55)/((3.61 xx 10^-8)^3 xx 6.022 xx 10^23`
= `254.2/(47.04 xx 10^-24 xx 6.022 xx 10^23)`
= `254.2/(283.27 xx 10^-1)`
= `254.2/28.327`
= 8.97 g cm−3
Thus, the calculated value is fairly in agreement with the measured value.
RELATED QUESTIONS
Ionic solids conduct electricity in molten state but not in solid state. Explain
Distinguish between crystalline solids and amorsphous solids.
How are the crystalline solids classified?
Answer the following in one or two sentences.
A solid is hard, brittle and electrically nonconductor. Its melt conducts electricity. What type of solid is it?
A compound is made up of two elements X and Y and crystallizes in bcc structure. Atoms of X are present at the corners of the cube. Atoms of Y are present at the centre of the cube. The formula of the compound is ______.
Classify the following solid:
Pb
In calcium fluoride, having the flurite structure the coordination number of Ca2+ ion and F− Ion are ____________.
Give any three characteristics of ionic crystals.
Which of the following is an example of molecular solid?
Which of the following is TRUE about molecular solids?
Fullerene is an example of ____________.
Which among the following is NOT a polar molecular solid?
Which among the following is not true for crystalline solid?
Which among the following is an example of network solid?
Order of increasing melting points among H2O(s), C(s), CS2 and Sn is ____________.
Which among the following is an example of non-polar molecule?
The hardest substance among the following is:
The compound, found in nature in gas phase but ionic in solid state is ____________.
Among solids, the highest melting point is exhibited by ____________.
Iodine molecules are held in the crystals lattice by ______.
Which of the following is not the characteristic of ionic solids?
Which of the following cannot be regarded as molecular solid?
(i) SiC (Silicon carbide)
(ii) AlN
(iii) Diamond
(iv) I2
NaCl type crystal (with coordination no. 6 : 6) can be converted into CsCl type crystal (with coordination no. 8 : 8) by applying ____________.
Why are liquids and gases categorised as fluids?
Which of the following exists as covalent crystals in the solid state?
Mention the res of the following solid:
Ice
Mention the res of the following solid:
CO2
Quartz is which type of crystal?
