Advertisements
Advertisements
प्रश्न
Define Anisotropy.
Advertisements
उत्तर
The ability of crystalline solids to change values of physical properties when measured in different directions is called anisotropy.
APPEARS IN
संबंधित प्रश्न
The major binding force in diamond is_______________ .
(a) Covalent bond
(b) Ionic bond
(c) Metallic bond
(d) Co-ordinate covalent bond
What is the covalency of nitrogen in N2O5?
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.
An ionic compound crystallises in FCC type structure with ‘A’ ions at the centre of each face and ‘B’ ions occupying corners of the cube. The formula of compound is _______.
Classify the following solids into different types:
a. Ammonium phosphate
b. Brass
c. S8 molecule
d. Diamond
Distinguish between crystalline solids and amorsphous solids.
Classify the following molecular solids into different types:
- HCl
- CO2
- Solid ice
- SO2
Account for the following :
o-nitrophenol is more steam volatile than p-nitrophenol.
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?
Answer the following in brief.
Distinguish between ionic solids and molecular solids
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 ______.
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
Assertion: monoclinic sulphur is an example of a monoclinic crystal system
Reason: for a monoclinic system, a ≠ b ≠ c and α = γ = 90°, β ≠ 90°
In calcium fluoride, having the flurite structure the coordination number of Ca2+ ion and F− Ion are ____________.
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.
NaCl
Classify the following solid.
Iodine
If NaCl is doped with 10−2 mol percentage of strontium chloride, what is the concentration of cation vacancy?
____________ is an example of molecular crystal.
Which among the following is NOT a polar molecular solid?
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 ____________.
Nature of binding forces present in carbon dioxide molecules in solid state are ____________.
Order of increasing melting points among H2O(s), C(s), CS2 and Sn is ____________.
What type of interaction hold the molecules together in a polar molecular solid?
Silicon carbide is an example of ____________.
London forces are present in ____________.
MgO has the structure of NaCl. The coordination number of the ions in MgO is ____________.
An AB2 type structure is found in ____________.
Solid CH4 is ____________.
Which of the following exists as covalent crystals in the solid state?
Which one of the following forms a molecular solid when solidified?
Which of the following is a network solid?
Which of the following is not the characteristic of ionic solids?
How many chloride ions are surrounding sodium ions in sodium chloride crystal?
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
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 \[\ce{0.04 \overset{\circ}{A}}\]
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 ______.
Among the following which is the best description of water in the solid phase?
Which of the following is not correct?
Mention the res of the following solid:
CO2
Quartz is which type of crystal?
