Preformulation - Solubility

Question 1

What is a solution?

Answer 1

Mixture of 2 or more components (solute + solvent) that form a single phase that is homogenous at molecular level

Question 2

What is a solute?

Answer 2

Component that is dissolved in the solvent in a solution

Question 3

What is a solvent?

Answer 3

Component that usually constitutes the bulk of the solution + determines its physical state

Question 4

What is concentration?

Answer 4

The proportion of a solute in a solution

Question 5

What is saturation?

Answer 5

Concentration = solubility

Question 6

What is sub saturation?

Answer 6

Concentration < solubility

Question 7

What is supersaturation?

Answer 7

Concentration > solubility

Question 8

What are the solute + solvent both?

Answer 8

Either polar or non-polar

Question 9

Why do solvent + solute have matching characteristics?

Answer 9

For intermolecular bonding

Question 10

What dictates overall polarity?

Answer 10

Proportions of polar + non-polar groups

Question 11

How can polarity be predicted?

Answer 11

From structure

Question 12

What is polarity?

Answer 12

Highly electronegative atom bonded covalently to a less electronegative atom

Question 13

What does polarity allow?

Answer 13

Dipole-dipole interactions
H bonds
Ion-dipole interactions

Question 14

What are non-polar molecules typically?

Answer 14

Hydrocarbons

Question 15

What happens to electronegativity down the group?

Answer 15

Decreases

Question 16

What happens to electronegativity across the group?

Answer 16

Increases

Question 17

Does a higher temperature always increase solubility?

Answer 17

NO

Question 18

What happens to at eqm?

Answer 18

Forward + reverse reactions proceed simultaneously at same rate

Question 19

What is bonding breaking?

Answer 19

Endothermic

Question 20

What is bond making?

Answer 20

Exothermic

Question 21

If solution cools, what it is?

Answer 21

Endothermic overall

Question 22

If solution warm, what is it?

Answer 22

Exothermic overall

Question 23

What is thermodynamic eqm?

Answer 23

Solute (s) ⇆ solute (aq)

Question 24

What is equation for acidic drug?

Answer 24

HA (aq) ⇆ H+ (aq) + A- (aq)

Question 25

What happens to acidic drug?

Answer 25

H+ leaves O = drug negatively charged + anion

Question 26

What is equation for basic drug?

Answer 26

B (aq) + H+ (aq) ⇆ BH+ (aq)

Question 27

What happens to basic drug?

Answer 27

Accepts H+ = positive charge + cation

Question 28

What happens if abundance of H+?

Answer 28

Favourable for basic drug

= acid neutral + basic cation

Question 29

What happens if shortage of H+?

Answer 29

Favourable for acid drug

= base neutral + acidic anion

Question 30

When is an acidic drug more soluble?

Answer 30

At high pH

Question 31

When is a basic drug more soluble?

Answer 31

At low pH

Question 32

What happens when you increase pH?

Answer 32

Remove H+ = favour acidic drug ionisation

Question 33

What is the common ion effect?

Answer 33

Solution tries to dissolve ionic drug as other ions already dissolved in solution

Question 34

Common ion effect

NaCl (s) ⇆ Na+ (aq) + Cl- (aq) EXAMPLE

Answer 34

Solution already contains abundance of Cl- from NaCl
=the reverse reaction will be favoured
= solubility of NaCl will be lower
= less dissolved