Advertisements
Advertisements
प्रश्न
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 _______.
पर्याय
AB4
A3B
AB
AB3
उत्तर
'A' ions are at the centre of each face. There are six face centres and each contributes one half to the unit cell. Total number of A ions present per unit cell
`=6 xx 1/2 = 3`.
'B' ions occupy corners of the cube. There are 8 corners and each contributes one eight to the unit cell.
Total number of B ions present per unit cell
`=8xx1/8=1`.
The formula of a compound is A3B
Hence, the correct answer is A3B.
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
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?
What type of solids are electrical conductors, malleable and ductile?
Explain The basis of similarities and differences 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.
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.
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 ______.
A compound crystallizes in bcc structure. What is unit cell edge length if diameter of its atom is 120 pm?
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
Define unit cell.
Give any three characteristics of ionic crystals.
Classify the following solid.
Brass
Classify the following solid.
NaCl
Classify the following solid.
Iodine
Which of the following is an example of molecular solid?
Which of the following is TRUE about molecular solids?
____________ is an example of molecular crystal.
Dry ice is an example of ____________.
Which among the following is NOT a polar molecular solid?
Lithium crystallizes into body centered cubic structure. What is the radius of lithium if edge length of it's unit cell is 351 pm?
Which among the following is not true for crystalline 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 ____________.
What type of interaction hold the molecules together in a polar molecular solid?
Ionization enthalpy is lowest in ____________.
Which among the following is an example of non-polar molecule?
Silicon carbide is an example of ____________.
MgO has the structure of NaCl. The coordination number of the ions in MgO is ____________.
The hardest substance among the following is:
The compound, found in nature in gas phase but ionic in solid state is ____________.
An example of a covalent crystalline solid is ____________.
Among solids, the highest melting point is exhibited by ____________.
Which one of the following forms a molecular solid when solidified?
Iodine molecules are held in the crystals lattice by ______.
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.
Why are liquids and gases categorised as fluids?
The major binding force in diamond, silicon and quartz is ______.
Which of the following molecules is non-polar in nature?
Which of the following is not correct?
Mention the res of the following solid:
Ice
What are intermolecular forces of attraction involved in molecular crystals?
