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
Solid A is a very hard electrical insulator in solid as well as in molten state and melts at extremely high temperature. What type of solid is it?
Sodium crystallizes in bcc structure. If the edge length of unit cell is 4.3 × 10-8 cm, the radius of Na atom is ______.
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
Give any three characteristics of ionic crystals.
Classify the following solid.
Brass
Classify the following solid.
Diamond
Classify the following solid.
Iodine
Which of the following is TRUE about molecular solids?
Fullerene is an example of ____________.
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?
London forces are present in ____________.
Solid CH4 is ____________.
An example of a covalent crystalline solid is ____________.
Which of the following exists as covalent crystals in the solid state?
Which one of the following forms a molecular solid when solidified?
Graphite cannot be classified as ______.
Which of the following cannot be regarded as molecular solid?
(i) SiC (Silicon carbide)
(ii) AlN
(iii) Diamond
(iv) I2
Which of the following is not true about the ionic solids?
An excess of potassium ions makes KCl crystals appear violet or lilac in colour since:
(i) some of the anionic sites are occupied by an unpaired electron.
(ii) some of the anionic sites are occupied by a pair of electrons.
(iii) there are vacancies at some anionic sites.
(iv) F-centres are created which impart colour to the crystals.
Which of the following cannot be regarded as molecular solid?
(i) SiC (Silicon carbide)
(ii) AlN
(iii) Diamond
(iv) I2
Why are liquids and gases categorised as fluids?
The covalent bond length is the shortest in which one of the following bonds?
Calculate the angle at which first order reflection will occurs in an X-ray spectrometer when x ~ rays of wavelength \[\ce{1.54 \overset{\circ}{A}}\] are diffracted by the atoms of a crystal given that inter planer distance is \[\ce{0.04 \overset{\circ}{A}}\]
Among the following which is the best description of water in the solid phase?
Which of the following is not correct?
