solid state of materials

Question 1

solids

Answer 1

Molecules tightly bound to each other by inter-molecular forces

Question 2

can solids flow

Answer 2

no

Question 3

solids are further sub-divided into?

Answer 3

Crystalline and Amorphous

Question 4

IM forces that make up solids

Answer 4

hydrogen bonds
van der Waals forces

Question 5

examples of van der Waals forces

Answer 5

Dipole-dipole
Dipole-Induced dipole Induced-induced

Question 6

can solids be a mixture of both the crystalline and amorphous sub- divisions

Answer 6

yes

Question 7

properties of amorphous

Answer 7

No long range order regular structure
Thermodynamically unstable
Show a “glass transition temperature” Tg (not a melting point)
Typically polymers (macromolecules)

Question 8

properties of crystalline

Answer 8

Typically made up of molecules packed in a regular defined order

Thermodynamically stable

Have a melting point (Mp)

Typically small molecules

Question 9

why does crystalline have a clear melting point wile amorphous has a temperature range for melting instead of a melting point

Answer 9

Each bond in crystal has equal energy to break while Many different bonds in amorphous, each requiring different energies to break

Question 10

the same molecules arranged in different crystal forms are called?

Answer 10

Crystal polymorphs

Question 11

each crystalline in a polycrystalline structure is called?

Answer 11

a grain

Question 12

polycrystalline

Answer 12

materials composed of multiple crystalline grains or crystals, each with its own individual orientation

Question 13

why should polymorphs be controlled

Answer 13

for regulatory approval

Question 14

dissolution

Answer 14

the process of a substance becoming solubilized or dispersed in a solvent, forming a solution

Question 15

enthalpy

Answer 15

thermodynamic quantity used to describe the total energy content of a system, including both internal energy and the energy associated with pressure and volume

Question 16

entropy

Answer 16

concept in thermodynamics that measures the degree of disorder or randomness in a system

Question 17

for a reaction or dissolution to happen spontaneously(automatically), what is required in terms of enthalpy and entropy

for the opposite of this to happen, what should be done?

Answer 17

low enthalpy
increased entropy

work should be done

Question 18

for a reaction to be spontaneous, which charge should Gibbs free energy be?

Answer 18

negative