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प्रश्न
Answer the following in brief.
Distinguish between ionic solids and molecular solids
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उत्तर
| Ionic solids | Molecular solids |
| 1. The constituent particles are charged ions (cations and anions). | 1. The constituent particles are monoatomic or polyatomic molecules |
| 2. The constituent particles are held by the electrostatic force of attraction between oppositely charged ions. | 2. The constituent particles are held by intermolecular forces of attractions such as London forces, dipole-dipole forces and/or hydrogen bonds. |
| 3. They are hard and brittle. | 3. They are soft. |
| 4. They have high melting points. | 4. They have low melting points. |
| 5. They are nonconductors of electricity in solid-state. However, they are good conductors when melted or dissolved in water. | 5. They are poor conductors of electricity. |
| 6. e.g. NaCl, CaF2, etc. | 6. Ice, benzoic acid, etc. |
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संबंधित प्रश्न
Ionic solids conduct electricity in molten state but not in solid state. Explain
Explain ionic solids are hard and brittle.
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
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 ______.
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Classify the following solid:
Pb
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Solid CO2 is an example of ____________.
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 ______.
Define unit cell.
Classify the following solid.
Brass
Classify the following solid.
Diamond
Select the INCORRECT match:
Which of the following is an example of molecular solid?
Which of the following is TRUE about molecular solids?
Which among the following is not true for crystalline solid?
Brass is an example of ____________.
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 ____________.
Among solids, the highest melting point is exhibited by ____________.
Which of the following exists as covalent crystals in the solid state?
The major binding force of diamond, silicon and quartz is ____________.
Which of the following is not the characteristic of ionic solids?
How many chloride ions are surrounding sodium ions in sodium chloride crystal?
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?
Inspite of long range order in the arrangement of particles why are the crystals usually not perfect?
Who introduced the term covalent bond?
Which of the following exists as covalent crystals in the solid state?
The major binding force in diamond, silicon and quartz is ______.
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 ______.
Which of the following is not correct?
Mention the res of the following solid:
CO2
What are intermolecular forces of attraction involved in molecular crystals?
