Chemistry

Solid State and Crystal Structures

151 Questions

Solid state chemistry focuses on the structural properties of crystalline solids. Questions cover Bravais lattices, unit cells, and close packed structures. This topic is essential for chemistry papers in UPSC and state PSC examinations.

Bravais lattice typesUnit cell calculationsClose packed structuresCrystal densityBragg's LawWurtzite structure

Solid State and Crystal Structures Questions

Multiple choice

Crystals usually found in stores are clear.

Directions: Read the following passage and answer the following question.

What are crystals? They are actually minerals that could grow in to a particular shape that they were supposed to be. The shape of a crystal is determined by various factors. We now know that our DNA determines the color of our eyes, how tall we shall get to be and what shape our bones would ultimately take. In the same way it is the chemistry of a mineral, i.e. the chemicals that a mineral is made of, that determines what shape its crystals would ultimately take. Thus it is possible to tell different minerals apart by analyzing the shape of their crystals.
 
Sometimes minerals form in limited spaces where there is very little room, so they don't acquire a proper crystalline shape. When there is just a big hunk of a mineral, we call it a massive mineral. When there is a definite shape with easily observable flat sides or layers, we call it a mineral crystal.

Most of the   crystals found on the earth were formed millions of years ago. Crystals form when rocks in liquid form inside the earth slowly cool and harden under typical conditions.   Crystals also form when liquids beneath the ground find their way into cracks and slowly deposit minerals in due course of time. It takes thousands of years for most mineral crystals to grow” into their usual shapes but a few   salts (like halite) can form so quickly that one can watch them grow at one’s own home!

Many people think that crystals as clear pretty stones that are used for jewelry. Amethyst is a commonly found quartz crystal. Crystals not have to be clear, however, those are the kinds you may usually see in jewelry stores.

 

  1. True

  2. False

  3. Can't say
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The passage states that while crystals don't have to be clear, 'those are the kinds you may usually see in jewelry stores.' This confirms that the crystals commonly found in stores (jewelry stores) are typically clear, which makes the statement true.

Multiple choice

Crystal formation is a process that always takes thousands of years.

Directions: Read the following passage and answer the following question.

What are crystals? They are actually minerals that could grow in to a particular shape that they were supposed to be. The shape of a crystal is determined by various factors. We now know that our DNA determines the color of our eyes, how tall we shall get to be and what shape our bones would ultimately take. In the same way it is the chemistry of a mineral, i.e. the chemicals that a mineral is made of, that determines what shape its crystals would ultimately take. Thus it is possible to tell different minerals apart by analyzing the shape of their crystals.
 
Sometimes minerals form in limited spaces where there is very little room, so they don't acquire a proper crystalline shape. When there is just a big hunk of a mineral, we call it a massive mineral. When there is a definite shape with easily observable flat sides or layers, we call it a mineral crystal.

Most of the   crystals found on the earth were formed millions of years ago. Crystals form when rocks in liquid form inside the earth slowly cool and harden under typical conditions.   Crystals also form when liquids beneath the ground find their way into cracks and slowly deposit minerals in due course of time. It takes thousands of years for most mineral crystals to grow” into their usual shapes but a few   salts (like halite) can form so quickly that one can watch them grow at one’s own home!

Many people think that crystals as clear pretty stones that are used for jewelry. Amethyst is a commonly found quartz crystal. Crystals not have to be clear, however, those are the kinds you may usually see in jewelry stores.

 

  1. True

  2. False

  3. Can't say
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The passage explicitly states that while 'it takes thousands of years for most mineral crystals to grow,' there are exceptions - 'a few salts (like halite) can form so quickly that one can watch them grow at one's own home!' The word 'always' in the statement makes it false.

Multiple choice

The shape of a crystal seldom depends on its constituent chemicals.

Directions: Read the following passage and answer the following question.

What are crystals? They are actually minerals that could grow in to a particular shape that they were supposed to be. The shape of a crystal is determined by various factors. We now know that our DNA determines the color of our eyes, how tall we shall get to be and what shape our bones would ultimately take. In the same way it is the chemistry of a mineral, i.e. the chemicals that a mineral is made of, that determines what shape its crystals would ultimately take. Thus it is possible to tell different minerals apart by analyzing the shape of their crystals.
 
Sometimes minerals form in limited spaces where there is very little room, so they don't acquire a proper crystalline shape. When there is just a big hunk of a mineral, we call it a massive mineral. When there is a definite shape with easily observable flat sides or layers, we call it a mineral crystal.

Most of the   crystals found on the earth were formed millions of years ago. Crystals form when rocks in liquid form inside the earth slowly cool and harden under typical conditions.   Crystals also form when liquids beneath the ground find their way into cracks and slowly deposit minerals in due course of time. It takes thousands of years for most mineral crystals to grow” into their usual shapes but a few   salts (like halite) can form so quickly that one can watch them grow at one’s own home!

Many people think that crystals as clear pretty stones that are used for jewelry. Amethyst is a commonly found quartz crystal. Crystals not have to be clear, however, those are the kinds you may usually see in jewelry stores.

 

  1. True

  2. False

  3. Can't say
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The passage clearly states that 'it is the chemistry of a mineral, i.e. the chemicals that a mineral is made of, that determines what shape its crystals would ultimately take.' This directly contradicts the statement that the shape 'seldom depends' on chemicals - it always depends on them.

Multiple choice

Minerals are always found in the form of crystals.

Directions: Read the following passage and answer the following question.

What are crystals? They are actually minerals that could grow in to a particular shape that they were supposed to be. The shape of a crystal is determined by various factors. We now know that our DNA determines the color of our eyes, how tall we shall get to be and what shape our bones would ultimately take. In the same way it is the chemistry of a mineral, i.e. the chemicals that a mineral is made of, that determines what shape its crystals would ultimately take. Thus it is possible to tell different minerals apart by analyzing the shape of their crystals.
 
Sometimes minerals form in limited spaces where there is very little room, so they don't acquire a proper crystalline shape. When there is just a big hunk of a mineral, we call it a massive mineral. When there is a definite shape with easily observable flat sides or layers, we call it a mineral crystal.

Most of the   crystals found on the earth were formed millions of years ago. Crystals form when rocks in liquid form inside the earth slowly cool and harden under typical conditions.   Crystals also form when liquids beneath the ground find their way into cracks and slowly deposit minerals in due course of time. It takes thousands of years for most mineral crystals to grow” into their usual shapes but a few   salts (like halite) can form so quickly that one can watch them grow at one’s own home!

Many people think that crystals as clear pretty stones that are used for jewelry. Amethyst is a commonly found quartz crystal. Crystals not have to be clear, however, those are the kinds you may usually see in jewelry stores.

 

  1. True

  2. False

  3. Can't say
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The passage distinguishes between two forms: 'when there is just a big hunk of a mineral, we call it a massive mineral' versus 'when there is a definite shape with easily observable flat sides or layers, we call it a mineral crystal.' This shows minerals are not always found as crystals - they can be massive minerals too.

Multiple choice

The total number of tetrahedral voids per unit cell in NaCl is

  1. 4

  2. 8

  3. Twice the number of octahedral voids

  4. Four times the number of octahedral voids

  5. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

NaCl has FCC arrangement of Cl ions. Hence, the number of Cl ions in packaging per unit cell= 4 Tetrahedral is double of octahedral voids. Thus, 2n= 8.

Multiple choice

Identify the incorrect statement(s):

  1. Pentaborane-11shows symmetrical square pyramidal geometry.
  2. CsBr crystal has face centred cubic structure.
  3. MgAl2O4 and Fe3O4 are identical in crystal structure.

  1. Only 1

  2. Only 2

  3. Only 3

  4. 1 and 2

  5. 2 and 3
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  1. Pentaborane-11 (B5H11) has an unsymmetrical square pyramidal geometry, in which five boron atoms occupy the five corners of a square pyramid.
    1. The crystal of CsBr has a body centred cubic structure.
    2. MgAl2O4 and Fe3O4 have spinel structures. Hence, statement 1 and 2 both are incorrect.