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
Explain the basis of similarities between metallic and ionic crystals.
Classify the following solids into different types:
a. Ammonium phosphate
b. Brass
c. S8 molecule
d. Diamond
Distinguish between crystalline solids and amorsphous solids.
Define Anisotropy.
Answer the following in brief.
Distinguish between ionic solids and molecular solids
Graphite and diamond are ____________.
An ionic compound AxBy crystallizes in fcc type crystal structure with B ions at the centre of each face and A ion occupying corners of the cube. the correct formula of AxBy is
The ionic radii of A+ and B− are 0.98 × 10−10 m and 1.81 × 10−10 m. The coordination number of each ion in AB is ______.
Classify the following solid.
P4
Classify the following solid.
Brass
Solid X is a very hard electrical insulator in solid as well as in molten state. It melts at extremely high temperature. Solid X is a ____________.
What type of interaction hold the molecules together in a polar molecular solid?
Ionization enthalpy is lowest in ____________.
Silicon carbide is an example of ____________.
The hardest substance among the following is:
An example of a covalent crystalline solid is ____________.
In graphite electrons are ____________.
Which one of the following forms a molecular solid when solidified?
Which of the following is a network solid?
Iodine molecules are held in the crystals lattice by ______.
Why are liquids and gases categorised as fluids?
A crystal with a ≠ b ≠ c and α = β = γ = 90° is
The covalent bond length is the shortest in which one of the following bonds?
A reddish-pink substance on heating gives off a vapour which condenses on the sides of the test tube and the substance turns blue. If on cooling water is added to the residue it turns to original colour. The substance is ______.
Graphite is a ______.
Mention the res of the following solid:
Ice
