UNIT#05 SOLIDS Flashcards
The transition temperature is shown by which of the following pairs:
➡Allotrope
➡Polymorph
(different crystalline forms of compounds)
Lattice energy decreases with the increase in the size of ion because oppositely charged ions
become less tight
Ionic solids are called true solids :
Crystalline
Which ionic solid has the lowest lattice energy
CsCl
Which of the following intermolecular forces are present in solid iodine:
(Iodine is non-polar)
London Dispersion force
Which one of the following is not amorphous solid:
Table salt
Ionic solids are called true solids
Crystalline
The transition temperature of sulphur is:
95.5 °C
Which of the following is isotropic property?
Metallic conduction
When an element exists in more than one crystalline form, it is known as:
Allotropy
A solid may be made up of:
➡Atoms
➡Molecuels
➡Ions
Which one has the highest melting point and boiling point
Covalent crystal
(Network Structure)
In a crystal, the atoms are located at the position of:
Minimum Potential Energy
(in order to gain maximum stability)
Which of the following is anisotropic
Quartz
(Crystalline)
Crystalline parts of otherwise amorphous solids are known as:
Crystallites
Coinage metals are Cu, Ag and Au and they have ___ crystalline system
Cubic
In the crystal structure of NaCl, the arrangement of Cl- ions are:
Face centred cubic
In a crystal lattice the correct sequence of bond angles is:
bc=α, ca=β, ab=γ
Total unit cell dimensions are;
SIx
The cubic crystal system has the following unit cell dimensions
a=b=c and α=β=γ=90°
The crystalline form of white tin is:
Tetragonal
Molecular crystals are;
Soft
Formed by intermolecular forces
The crystals formed due to London forces of interaction are:
Molecular
The number of Cl- ions per units cell of a simple cubic lattice at the corer is/are:
1
Which is incorrect about the structure of iodine
I-I (g) > I-I (s)
Bond length
The coordination number of each ion in NaCl is:
6
The best conductors of electricity are;
Metallic solids
Independent molecule of NaCl may exist in:
Vapour Phase
Which of the following is an example of a polar molecular solids
Sugar
(have hydrogen bonding)
Solid CO2 (Dry ice) is an example of ___crystal
Molecular
(non-polar)
The coordination number of Na in the NaCl crystal is;
6
In the structure of NaCl, each sodium ion is surrounded by chloride ions
6
Which one of the following has the highest lattice energy
LiCl
The electrical conductivity of graphite is greater in one direction than in another due to;
Anisotropy
In diamond, each o the four outer electrons on every carbon atom is involved in covalent bonding. This means that there are no free electrons available. Which of the following property is explained by this statement
Diamond does not conduct heat and electricity
Graphite is one of the allotropic forms of Carbon it is;
➡Anisotrpic
➡Good conductor of electricity
A substance that has a sharp melting point in the following is
Diamond
(Crystalline solid)
The lattice energy is also called:
Crystal Energy
Which of the following is also an isomorph o copper?
Ag
Highest vapour pressure
Molecular solids
The molecular theory for metallic solids is;
Electron Gas Theory
Position of particles in crystalline solids represented by:
Lattice Point
The shape of iodine unit cells
Cubic
Radius ratio has units
Unitless
CuSO4.5H2O is an example of a crystal system
Triclinic
Which of the following solids is isotropic?
Amorphous solids
Properties due to a change of direction are called ___
Anisotropy
Which of the following has a transition temperature equal to 128 degrees celsius?
Na2CO3
Polymorphs have different:
Physical Properties
Allotropy is for:
Elements
HF has a higher boiling point than HCl due to:
Hydrogen bonding
Isomorphism is shown by:
➡Ionic solid
➡Metallic solid
➡Coinage metal
Current in electrolysis is carried through:
➡Postive ions
➡Negative ions
The most asymmetrical crystal system:
Cubic
Which one of the characteristics of ionic solids?
Solubility in polar solvents
The size and shape of the crystal depend upon some crystallographic elements which are:
6
The deliquescence is a property in which a solid
Absorbs moisture and turns to liquid form
Which one of them is known as supercooled liquids?
Glass
To conduct electricity through ionic solid, ions should be
Free
The smallest part of the crystal lattice has all the properties of the entire crystal this is called:
Unit cell
Lattice points are also called:
Lattice sites
The definite shape of NaCl crystal is its:
Habit
Which of the following are isomorphs
NaNO3, KNO3
Symmetry is the repetition of ___ when a crystal rotates at 360 ° along its axis
➡Faces
➡Angles
➡Edge
Which of the following is a directional bond?
H-bond
The thermal conductivity of graphite is greater when a mobile electron is moving to its layers
Parallel
Which of the following is true regarding polymorphism
same chemical properties
Types of solids on basis of bonds present in them
4
Ionic solids are;
Brittle
The coordination of a number of Na in NaCl
6
NaNO3 as unit cell
Rhombohedral
2 sides of the unit cell and 3 angles are equal in;
Tetragonal
Molecular solids are:
Bad conductors of electricity
The lattice energy of NaCl:
-787 kJ/mol
Metallic solids are:
Good conductor
Which is true about copper:
Can be easily bent
Lattice energy decrease when:
Charge to-size ratio decreases
Which one of the following is a giant molecule
SiO2
Molecular crystals are
Soft
The overall structure of diamond looksIce occupies more space than liquid water
Hexagonal
Ice occupies more space than liquid water
9%
The crystals formed due to London forces of interaction are
Molecular
The number of chloride ions per units cell of a simple cubic lattice at the corner is/are
1
Ionic solids are characterized by
Solubility in polar solvents
Which is incorrect about Structure of Iodine
I-I(g) < I-I(s) bond length
Overall ratio of silicon to oxygen atoms in silicon (IV) oxide is
1: 2
C-C Bond length in Diamond crystal are
154 pm
In interior of silicon (IV) oxide crystal, each Silicon atom is directly connected with
Four oxygen atoms
Iodine is a molecular solid because the forces between its molecules are
Van der Waals forces
The coordination number of each ion in NaCl is
6
The best conductors of electricity are
Metallic solids
Which of the following statement is incorrect about silica
Has very high thermal expansion
During which process empty spaces between particles become minimum
Condensation
A solid maybe made up of
Atoms, Ions or molecules
A malleable solid is one which can be
Converted into thin sheets
Which solids are called true solids
Crystalline solid
The arrangement ABC,ABC… is referred as
cubic close packing
Crystalline solids are classified on the basis of bonding into ______ types
4
Ionic crystals are characterized by
Solubility in polar solvents
NaCl crystal is
Cubic
Which element exists as discrete small molecule in the solid state
Iodine
Ice floats on the liquid water because
Water freezes at 0°C and is less dense than liquid water
Number of tetrahedral carbon atoms in unit cell of diamond is
4
The number of chloride ions per unit cell of NaCl are
4
The Crystal of diamond is
Covalent
1 unit cell of NaCl contains ion pairs
4
Which is not the property of silica
High thermal expansion
Silicon(IV) oxide crystal is an example of
Covalent crystal
Carbon atom in diamond is
sp3 hybridized
The given crystal lattice is for
Iodine
The volume of ice on freezing 200cm3 of water will be
218cm3
I - I Bond distance difference between i2(g) and i2(s) is
4.9 pm
Which one of the following contains maximum hydrogen bonding
H2O
Ammonia shows the maximum boiling point because of
Enhanced electronegativity character of nitrogen
The boiling point of H2O is 100°C while that of C2H5OH is 78.37°C. The reason is that
The number of hydrogen bonds per water molecule is greater than C2H5OH
All are crystalline solids except
Glass
Which is a pseudo solid?
Glue
____ may be isotropic under ordinary conditions:
Bromine
NaCl and CsF have same geometry because:
They have similar radii ratio
K2SO4 and K2CrO4 are isomorphic substances they have similar properties except one:
Chemical Properties
In structure of NaCl, the number of formula units per unit cell is:
4
Ionic solids are mostly of high density due to:
Close packing of ions
The molecuels of CO2 in dry ice form the:
Molecular Crystals
The arrangement of particles as a points in a crystal is called:
➡Crystal Lattice
➡Space Lattice
Unit cell is the smallest part and represented all features of the entire ____
Crystal
Crystalline solids have different properties;
1. Allotropy
2. Isomorphism
3. Polymorphism
Ionic compounds show which of the above properties:
➡II
➡III
Which property is incorrect about silica:
➡High transparency of light❌
➡Very low thermal expansion❌
➡Excellent insulator❌
➡Soluble in water✅
Which of the following is wrong?
➡Water has maximum density at 4°C❌
➡Molecular solids are relatively soft and volatile❌
➡In graphite carbon atom has tetrahedral geometry✅
➡Graphite is a good conductor of electricity❌
Which one is not the anisotropic behaviour:
➡Cleavage of crystal❌
➡Electrical Conductivity❌
➡Co-efficient of thermal expansion❌
➡Melting Point and Boiling Point✅
Which of the following is anisotropic?
Crystalline Solid
The lattice energy is maximum for:
MgF2
Ionic solids do not conduct the electrical current because:
Ions dont have translatory motion
The number of ion pairs per unit cell of NaCl are:
4
Crystalline solids are classified on the basis of bonding into;
Four types
In a crystal lattice the correct sequence of bond angles is:
bc=α, ca=β, ab=γ
The number of Cl-1 ions per unit cell of NaCl is;
4
The crystal of a diamond is;
Covalent
One unit cell of NaCl contains ion pairs:
Four
The share of Na+ ion on each edge in the NaCl unit cell is;
1/4
Silicon (IV) oxide crystal is an example of;
Covalent Crystal
The carbon atom in a diamond is;
sp3 hybridized
The given crystal lattice is for:
Iodine
The volume of ice on freezng 200 cm^3 of water will be:
218 cm^3
I-I bond distance difference between I2 and I2 is:
4.9 pm
Molecules in dry ice forms:
Covalent Crystal
Ionic solids are characterized by:
Solubility in a polar solvent
The lattice energy of NaCl is;
-787 kJ/mol
Which of the following is layered covalent crystalline solid
Cadmium Iodide
Maximum lattice energy is shown by:
LiCl
One unit cell of NaCl contains ion pairs;
Four
Which is incorrect about the structure of iodine;
➡Face-Centered Cubic❌
➡Metallic Appearance❌
➡I-I(g) > I-I(s)✅
➡I-I(g) < I-I(s)❌
The overall ratio of silicon to oxygen atoms in silicon (IV) oxide is;
1:2
C-C bond lengths in the diamond crystals are;
154 pm
The rate of evaporation of a liqui d does not depend on:
Material of container
Type of hybridization in diamond:
sp3
The overall structure of the diamond looks;
Face-centred cubic
The number of Cl-1 ions per unit cell of NaCl is;
4
The crystal of a diamond is;
Covalent
The crystals formed due to London forces of interaction are:
Molecular
The number of Cl-1 ions per unit cell of a simple cubic lattice at the corner is/are:
1
