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