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Multiple choice chemistry solid state classification of crystalline solids classification of solids introduction to solids

Which of the following is not true about the ionic solids?

  1. Bigger ions form the close packed structure.

  2. Smaller ions occupy either the tetrahedral or the octahedral voids depending upon their size.

  3. Occupation of all the voids is not necessary.

  4. The fraction of octahedral or tetrahedral voids occupied depends upon the radii of the ions occupying the voids.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In ionic solids anions (which are normally longer in size than cations forms closed pack array. 

The cation occupies one of the two types of holes remaining between the anions (either tetrahedral void or octahedral void). 
Depending on the relative sizes of cations and anions, the voids are filled. Occupation of voids depends on the stoichiometry of the compounds. It is not necessary that all voids get filled.

Multiple choice chemistry solid state classification of crystalline solids classification of solids introduction to solids

What makes the molecular crystals solid at low temperature?

  1. Sharing of electrons.

  2. Transfer of electrons.

  3. Vander Waal's force arising out of polarisation.

  4. All of the above.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Vander Waal's forces make the molecular crystals, solids at low temperature.


Its properties are dictated by the weak nature of these intermolecular forces.

Multiple choice chemistry solid state classification of crystalline solids classification of solids introduction to solids

A molecular crystalline solid:

  1. is very hard

  2. is volatile

  3. has a high melting point

  4. is a good conductor
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Molecular solid is a solid in which the constituent particles are atoms or molecules which are held together by weak intermolecular forces i.e. van der Waals forces. Due to weak forces, they are volatile.

Multiple choice chemistry solid state classification of crystalline solids classification of solids introduction to solids

$KCl(s)$ is:

  1. An ionic substance

  2. A polar covalent substance

  3. A nonpolar covalent substance

  4. An amorphous substance

  5. A metallic network
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Potassium chloride KCl is a metal halide salt composed of potassium and chloride. It is odorless and has a white or colorless vitreous crystal appearance. The solid dissolves readily in water and its solutions have a salt-like taste.


In aqueous solution,

$KCl\longrightarrow { K }^{ + }+{ Cl }^{ - }$

It is an ionic substance in solid state.

Multiple choice chemistry solid state classification of crystalline solids classification of solids introduction to solids

This allows many solids to conduct electricity :

  1. Hydrogen bonding

  2. Ionic bonding

  3. Metallic bonding

  4. Nonpolar covalent bonding

  5. Polar covalent bonding
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation


Metallic bonding is the strong attraction between closely packed positive metal ions and a sea of delocalised electrons. The delocalised electrons are able to move through the metallic structure. When a potential difference  is applied, they will move together, allowing an electric current to flow through the metal.

Multiple choice chemistry solid state classification of crystalline solids classification of solids introduction to solids

$I$. Metallic solids tend to be very brittle.

$II$. Metallic bonds are broken quite easily.

  1. Statement $I$ is true, Statement $II$ is true
  2. Statement $I$ is true, Statement $II$ is false
  3. Statement $I$ is false Statement $II$ is true
  4. Statement $I$ is false, Statement $II$ is false
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Metallic solids are generally non-brittle or highly malleable and ductile. Also metallic bond is one of the strongest bonds. 

Therefore both statements are false.

Multiple choice chemistry solid state classification of crystalline solids classification of solids introduction to solids

Which of the following statements is true?

  1. Molecular crystals are very hard and incompressible

  2. Ionic crystals have very low volatility

  3. Metallic bond is directional and rigid

  4. Boron nitride has an ionic crystal structure
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ionic crystals have very low volatility. Generally, ionic solids are having ionic bonds between the constituent atoms. 

Ionic bonds are very strong bonds. So they are less volatile.