Midterms (12 & 13)

Question 1

three possible types of mixtures

Answer 1

1. coarse mixtures
2. colloidal dispersion
3. true solution

Question 2

the individual particles are readily discernible and may be seperated from each other by mechanical means.

Answer 2

coarse mixture

Question 3

the particles are much finer and the heterogeneity is not so readily apparent

Answer 3

colloidal dispersion

Question 4

the constituents cannot be separated from each other by mechanical means

Answer 4

true solution

Question 5

the substance that dissolves

Answer 5

solute

Question 6

the substance in which solution takes place

Answer 6

the solvent

Question 7

can exist only in the absence of dissolving substance and is at best very unstable

Answer 7

super saturated solution

Question 8

nature of the solute and solvent, the temperature and the pressure, ethyl alcohol and water

Answer 8

factors affecting solubility

Question 9

ethyl alcohol and water

Answer 9

completely miscible

Question 10

water and mercury

Answer 10

completely immiscible

Question 11

the type of distillation described heretofore, in which the vapor removed is in equilibrium with the total mass of boiling liquid

Answer 11

equilibrium distillation

Question 12

distillation of immiscible liquids is utilized industrially and in the laboratory for the purification of organic liquids which either boil at high temperatures or tend to decompose when heated to their normal boiling pount

Answer 12

steam distillation

Question 13

states that at constant temperature that solubility of a gas in a liquid is directly proportional to the pressure of the gas above the liquid

Answer 13

Henry’s Law

Question 14

Henry’s Law constant

Answer 14

proportionally factor K

Question 15

four properties of solutions containing non-volatile solutes

Answer 15

1. the vapour pressure lowering of the solvent
2. the freezing point lowering
3. the boiling point elevation
4. the osmotic pressure

Question 16

any property which depends only on the number of particles in solution and not in any way on the nature of these

Answer 16

colligative property

Question 17

the difference between the boiling points of the solution and pure solvent at any given constant pressure

Answer 17

boiling point elevation of the solution

Question 18

the proportionally constant k is called

Answer 18

molal boiling point elevation constant or the ebullioscopic constant

Question 19

ether and water

Answer 19

partially miscible

Question 20

when a dilute solution is cooled, a temperature is eventually reached at which solid solvent begins to separate from solution. the temperature at which this separation begins is called

Answer 20

the freezing point of the solution

Question 21

boiling point elevation. K

Answer 21

molal freezing point lowering or cryoscopic constant

Question 22

the mechanical pressure which must be applied on a solution to prevent osmosis of the solvent into the solution through a semi-permeable membrane

Answer 22

osmotic pressure of the solution

Question 23

which states that a susbtance will distribute itself between two solvents until at equilibrium the ratio of the activities of the substance in the two layers is constant at any given temperature

Answer 23

Nernst distribution law

Question 24

constant K is called either the

Answer 24

distribution or partition coefficient

Question 25

first called a attention to the fact that the above statement of the distribution law is valid only when the solute undergoes no change such as dissociation or association

Answer 25

Walter Nernst

Question 26

there are substances which when dissolved in water or other appropriate solvents yield solutions which conduct electricity to a greater or lesser extend. Such solutions are said to be

Answer 26

electrolytes

Question 27

the ratio of the colligative effect produced by a concentration m of electrolyte divided by the effect observed for the same concentration of non-electrolyte

Answer 27

van’t Hoff i

Question 28

the colligative properties of electrolytes and the fact that solutions of electrolytes conduct electricity led Svante arrhenius to propose in 1887 his celebrated

Answer 28

theory of electrolytic dissociation

Question 29

postulated that electrolytes in solution are dissociated into electrically charged particles, called ions, in such a manner that the total charge on the positive ions is equal to the total charge on the negative ions.

Answer 29

arrhenius

Question 30

solutions of substances that show good condutance and which indicate a high degree of dissociation in solution are designated as

Answer 30

strong electrolytes

Question 31

solutions of substances that exhibit only poor conductance and a low degree of dissociation are called

Answer 31

weak electrolytes

Question 32

published a theory of interiohic attraction in dilute solutions of electrolytes which occupies a dominant position in all considerations involving electrolytes and their kinetic and thermodynamic behavior

Answer 32

1923 P. debye and E. huckel

Question 33

postulate that strong electrolytes exist in solution as ions of the types mentioned, they believe that strong electrolytes, at least in dilute solutions, are completely ionized and that the effects observed are due to the unequal distribution of ions resulting from interionic attraction

Answer 33

Debye and Huckel

Question 34

the effect of the concentration of the ions enters through a quantity called the

Answer 34

ionic strength of the solution