The Solid State Flashcards
We need solids with widely different properties(as conductors, as none conductors, as polymers etc).These properties depend upon? How we can discover solids with better properties?
The nature of constituent and binding forces between them, that gives particular structure.means properties of solids depend on structure of solids.Thats why study of structure of solids is imp and correlate it with properties to discover new solids.
How the structure of solids is diff from fluids.what explains rigidity of solids?
In solids the constituent particles have fixed positions and can oscillate only about their mean positions.
What is the basic feature of crystalline solid?
The constituent particles are arranged in regular patterns.
Why solids have various types of structure(fundamental not chair table type)
Different possible arrangements of particles.
Under a given set of conditions of temp and pressure , a substance can be solid,gas or liquid as their stable state depending on?
Net effect of intermolecular interaction and thermal energy.
What happens to a substance at very low temp?
At low temp, thermal energy is low and intermolecular forces bring them so close that constituent particles cling to one another and occupy fixed positions.these particles can oscillate about their mean position, and substance exist as solid.
Solids can be divided into which types based on the nature of order present in the arrangement is their constituent particles.
Amorphous-short range order-irregular patter
Crystalline -long range order-regular pattern
Examples of crystalline solid
NaCl And quartz
Example of amorphous solid
Quartz glass, plastics, rubber
Difference between melting points of amorphous and crystalline solids
Amorphous -have a range of temperature over which it melts and softens,this these solids can be blended into various shapes
Crystalline-have sharp melting point
Can amorphous solids be converted into crystalline , how?example?
On heating , at some point.
Some ancient glass have become milky due to crystallization.
How amorphous solids and liquids related?
They both have tendency to flow.
Which solid is anisotropic and which is isotropic and why?
Crystalline-anisotropic -diff arrangement of particles in diff direction
Amorphous -isotropic-similarly irregular arrangement in all directions
Which solid have definite shape and which has irregular shape?
Crystalline-definite
Amorphous -irregular
Cleavage property of two solids
Amorphous -shows irregular surfaces when cut
Crystalline-shows plain and smooth surfaces when cut with sharp edges tool
Which solid has definite and characteristic heat of fusion?
Crystalline
Which solids are called pseudo solids or super cooled liquids
Amorphous
Which solid is the best photovoltaic material available?
Amorphous silicon
All metallic ,none metallic and compounds belongs to which solid
Crystalline
Classification of crystalline solids on the basis of nature of intermolecular forces of interaction operating in them?
Molecular
Ionic
Metallic
Covalent
What are the constituent particles of molecular solids, also tell exception.
Molecules
Atoms in case of non polar molecular solids ex argon and helium
What are the three types of molecular solids
None polar molecular solids
Polar molecular solids
Hydrogen bonded molecular solids
What are the constituent particles of non polar molecular solids
Atoms in argon or helium or
molecules formed by non polar covalent bond like H2,Cl2 and I2 etc.
What type of intermolecular interactions are seen in nonpolar molecular solids
Weak Dispersion forces or London forces
What are the constituent particles of polar molecular slids
Molecules formed by polar covalent bond like HCl, SO2 etc
What type of intermolecular forces actin polar molecular solids
Dipole dipole interactions
Whose melting point is higher, polar molecular solids or non polar molecular solids?
Polar molecular solids
What are the constituent particles of hydrogen bonded molecular solids
Molecules having polar covalent bonds between H and F, 0 or N
Which physical property of hydrogen bonded molecular solids is different from other two types of molecular soilds
They are volatile liquids or soft solids at room temp and pressure
How are ionic solids formed?by which interaction?
By the 3D arrangement of anions and cations bound by strong coulombic(electrostatic) forces.
What is the physical nature and properties if ionic solids?
Brittle and hard
High melting and boiling point
In which state and when are ionic solids conductors?
In molten state or when dissolved in water.
In these states ions are free to move about not in solid state
Structurally how are metallic solids
Orderly collection of positive ions surrounded by and held together by a sea of free electrons
What causes thermal and electrical conductivity in metallic solids
Free electrons
What causes lustre and colour in metallic solids
Free electrons
What are covalent or network solids
Solids of non metals that result from the formation of covalent bonds between adjacent atoms throughout the crystal.
What is giant molecule?
Crystal of network or covalent solids are called giant molecules because they are formed by covalent bonds throughout the crystal
Why covalent or network solids are very hard and brittle
Due to covalent bonds throughout the crystal.because covalent bonds are(covalent bonding as intermolecular bonding is very strong as compared to other intermolecular interactions such as dipole dipole,h bonding,electrostatic etc because covalent bonds are usually used as chenical bonding basically to make molecules if we use this strong bonding between two molecules also this creates very very strong a giant molecule type structure) strong and directional.
Why covalent solids are insulators ?
Because all the electrons are involved in covalent bonding ,there are no free electrons and can’t come out even in molten state or in water.
Why graphite being an covalent solid a conductor of electricity and soft in nature?
Due to their exceptional structure, carbon atoms are arranged in different layers each carbon atom is bonded to three adjacent atoms and fourth valence electron is free to move about between layers which cause electricity conduction.diff layers can slide over one another which causes softness.
What is the length of bonds in giant molecule/crystal of diamond?
154pm
What is the length of carbon carbon bond and bond between two layers in graphite
C - C bond-141.5 pm
Between layers-340 pm
Which crystalline solids are conductors?
Metallic solids and graphite*exceptional of covalent solids.
Examples of covalent solids
Diamond,silicon carbide,SiO2(quartz),AlN,graphite
Which solids are hard but malleable and ductile
Metallic solids
Which solids are hard and brittle
Ionic solids
What type of solid CCl4 is?
Non polar molcular solid
What type of solid CO2 is
Non polar molecular solid
