solubility definitions

Question 1

solution

Answer 1

homogeneous mixture of 2 or more pure substances. solutions consist of particles/molecules/ions ≈ 0.1-2 nm in size dispersed in solvent (too small to be seen)

Question 2

solvent

Answer 2

substance in which solute is dissolved

Question 3

solute

Answer 3

substance dissolved in solvent

Question 4

solubility

Answer 4

maximum amount of solute that dissolves completely in given amount of solvent at particular temperature + pressure

Question 5

saturated solution

Answer 5

solution in which no more solute will dissolve

Question 6

supersaturated solution

Answer 6

solute present in solution above its normal solubility limit

Question 7

dissolution

Answer 7

process of dissolving solute in solvent to give homogenous solution

Question 8

dissolution rate

Answer 8

proportional to maximum equilibrium solubility

Question 9

What is the process of dissolution?

Answer 9

1) drug molecule removed from its crystal
2) cavity for molecule created in solvent
3) drug molecule inserted into cavity

Question 10

What factors have a major effect on solubility?

Answer 10

1) surface area

2) nature of functional groups on solute

Question 11

What structural factors determine solubility?

Answer 11

1) molecular surface area/weight

2) hydrophobic/hydrophilic ratio + position of substituents

Question 12

How does molecular surface area effect solubility?

Answer 12

1) determines number of solvent particles that can pack around solute molecule
2) surface area affected by linear/branched structure
3) boiling/melting point reflects interactions within molecules

Question 13

How does molecular weight effect solubility?

Answer 13

increasing molecular weight decreases solublity

Question 14

How does hydrophilic/hydrophobic ratio effect solubility?

Answer 14

1) polar/non-polar portions of the drug interact in different ways with solvent
2) the greater the area of hydrophilic portion relative to area of hydrophobic portion, the greater the aqueous solubility
3) nature of substituents

Question 15

Is -OH hydrophilic/hydrophobic?

Answer 15

hydrophilic

Question 16

Is -CH₃ hydrophilic/hydrophobic?

Answer 16

hydrophobic

Question 17

solvation

Answer 17

process of binding solvent to solute molecules

Question 18

hydration

Answer 18

when solvent is water

Question 19

bulk structure of water

Answer 19

molecules of water present in a specific orientation

Question 20

How do cations bind water?

Answer 20

strongly, retaining layer of water even in crystal form

Question 21

structure breakers

Answer 21

monovalent/monoatomic cations that bind 4 molecules of water, modifying bulk structure of water

Question 22

structure makers

Answer 22

ions that increase structured nature of water