States of Matter

Question 1

Cohesion and adhesion are manifestations of_____ bonding.

Answer 1

Intermolecular

Question 2

A system is more stable at what point

Answer 2

When the repulsive and attractive forces are in equilibrium

Question 3

What governs The balance of forces between two molecules

Answer 3

governed by the negatively charged electron clouds of the molecules.

Question 4

relates to NON IONIC interaction between molecules

Answer 4

Van Der Waal forces

Question 5

Give eg of PERMANENT van der wall dipoles

Answer 5

Keesom forces(dipole-dipole) eg.
Peptide bonds and HCl intermolecular bonds

Question 6

What are Debye forces

Answer 6

Induced dipole interactions

Eg. Condensation of non polar gas to for liquids or solids

Question 7

Relationship between potential energy and distance btn molecules

Answer 7

Potential energy is inversely proportional to the distance of separation raised to the power 6

P.E=k 1/d^6

Question 8

What interaction shows the ability of a permanent dipole to polarise a neighbouring non polar molecule (which are easily polarisable)

Answer 8

Debye forces or dipole induced dipole.

Question 9

What are London forces and eg

Answer 9

induced dipole induced dipole attraction

two neighbouring non polar neutral molecules induce partial charge distribution

Eg. conceptualise aliphatic chains in the lipid core of a biologic membrane
Found in Noble gases, diatoms ( O2, H2,N2) and others- Ch4

Question 10

What interactions account partly for the solubility of ionic crystalline structure in water

Answer 10

Ion dipole interactions
Eg, NaCl and Water

cation Na+ attracts the relatively charged negative oxygen and the anion Cl- attracts the hydrogen atoms of the dipolar water molecules.

Question 11

interaction that involves charged moieties.

Answer 11

Ion ion interactions or ionic bonds

Question 12

Weaker ion-ion interactions in salt forms are eg of what interaction

Answer 12

Ion ion interaction

Question 13

The interaction of a hydrochloride salt of a drug and

salt bridge between counter ions in protein molecules exhibit what interactions

Answer 13

i) Ion ion interaction that is intermolecular

ii) intermolecular ion ion

Question 14

What properties of pharmaceutical agents does the strength of ion ion interaction have profound effect

Answer 14

pka, pH, solubility

Question 15

Interaction between a molecule containing hydrogen and a strong electronegative atom (F, O, N)

Answer 15

H bonding

Question 16

Who discovered H bonds

Answer 16

latimer and Rudebush in 1920

Question 17

Hydrogen bonds can exist between alcohol molecules, carboxylic acids, aldehydes, esters and polypeptides

T or F

Answer 17

True

Question 18

solids with high vapour pressure upon heating undergo?

Answer 18

Sublimation

Question 19

What are ideal gases

Answer 19

1. No molecular interaction exist between molecules

2. Collisions perfectly elastic

Question 20

Boyle’s law

Answer 20

P α 1/v, PV =k

Question 21

Gay lussac and Charles Law

Answer 21

V α T, V =Kt

Question 22

Combined gas law

Answer 22

P1V1/T1= P2V2/T2

Question 23

Change Celcius to Kelvin

Answer 23

Kelvin = Celsius + 273.15.

Question 24

general ideal gas law

Answer 24

PV = nRT …… 5

Question 25

Why is the general ideal gas law called equation of state of an ideal gas

Answer 25

because it relates pressure, volume and temperature of a given mass of gas

Question 26

How do you find the molecular weight of a gas with the ideal gas law

Answer 26

``` n = m/M, replacing n in the formula PV = nRT = mRT/M M = mRT/PV ```

Question 27

Equation for real gas

Answer 27

Page 23

Question 28

What is critical temperature

Answer 28

temperature when exceeded no amount of pressure can cause the gas to liquify.

Question 29

What is critical pressure

Answer 29

The pressure required to liquify a gas at the critical temperature

Question 30

What is highest vapour pressure liquid can have.

Answer 30

Critical pressure

Question 31

What is the critical temp and pressure of water and helium

Answer 31

Critical temp for water 647K at critical pressure of 218atm, that of Helium is 5.5k, 2.26atm

Question 32

the gas phase of substance that is normally liquid at room temperature

Answer 32

Vapor

Question 33

What variable affects vapor pressure

Answer 33

Temperature only | As T increases Vo increases

Question 34

When vapour pressure is equal to atmospheric pressure what happens

Answer 34

, there is boiling.

Question 35

State the Clausius- Claypeyron equation

Answer 35

log 𝑃2 /P1= ∆𝐻𝑣 𝑇2−𝑇1/ 2.303𝑅𝑇1𝑇2 Hv is the molar heat of vaporization, that is, the heat absorbed by 1 mole of liquid when it passes into the vapor state.

Question 36

Solids are incompressible | T or F

Answer 36

True

Question 37

Morphology of crystalline form of a solid is called____

Answer 37

crystal habit

Question 38

What are the 6 crystal systems

Answer 38

Cubic – sodium chloride Tetragonal – urea Hexagonal – iodoform Rhombic – iodine Monoclinic – sucrose Triclinic – Boric acid

Question 39

How does carbon show polymorphism

Answer 39

diamond in a cubic (tetrahedral lattice arrangement) Graphite in sheet of a hexagonal lattice

Question 40

When change from one polymorphic form to the other is reversible , the compound is called___

Answer 40

enantiotropic

Question 41

If the change of one polymorphic form to another is just in one direction it is called –.

Answer 41

monotropic

Question 42

Characteristics of a stable polymorphic form of a solid and metastable( unstable)

Answer 42

Stable polymorph represents the lowest energy state, has highest melting point and least aqueous solubility. Metastable form represent the higher energy state, have lower melting point and high aqueous solubility

Question 43

How do metastable form convert to stable

Answer 43

Metastable form converts to the stable form due to their higher energy state.

Question 44

What polymorphic form shows better bioavailability and therefore preferred in formulations.

Answer 44

Metastable

Question 45

What are solvates

Answer 45

solvent traces in the crystal lattice formed when crystallization occurs. It forms part of the crystal lattice and affects its properties

Question 46

What are amorphous solids

Answer 46

They differ from crystalline solids in that they tend to flow when subjected to sufficient pressure over a period of time, and they do not have definite melting points.

Question 47

Give an eg of how a drug being amorphous or crystalline affects its therapeutic activity.

Answer 47

crystalline form of the antibiotic novobiocin acid is poorly absorbed and has no activity, whereas the amorphous form is readily absorbed and therapeutically active. This is due to the differences in the rate of dissolution