Module 7

Question 1

is defined as the ratio of the colligative effect produced by a concentration, m of electrolyte divided by the effect observed for the same concentration of nonelectrolyte

Answer 1

i

Question 2

who suggested to use i factor

Answer 2

Van’t Hoff

Question 3

Classification of Electrolytes

Answer 3

Strong Electrolytes
Weak Electrolytes

Question 4

are solutions that show good conductance and which indicate a high degree of dissociation

Answer 4

Strong Electrolytes

Question 5

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

Answer 5

Weak Electrolytes

Question 6

Subdivisions of strong electrolytes

Answer 6

1-1
2-1
1-2
2-2
1-3
3-1
3-2

Question 7

1-1 type Example

Answer 7

HCl

Question 8

2-1 type Example

Answer 8

Ba(NO3)2

Question 9

1-2 type Example:

Answer 9

K2SO4

Question 10

2-2 type Example

Answer 10

CaSO4

Question 11

1-3 type Example

Answer 11

H3PO4

Question 12

3-1 type Example

Answer 12

AlCl3

Question 13

3-2 type
Example

Answer 13

Fe2 (SO4) 3

Question 14

states that the electrolytes will dissociate into electrically charged particles, called ions, in such a manner that the total charge of (+) ions is equal to the total charge of (-) ions. Despite of the presence of these charged particles, the net result is a neutral solution.

Answer 14

Arrhenius Theory of Electrolytic Dissociation

Question 15

It states that each ion in the solution is surrounded by an ionic attraction whose net charge is opposite to that of the central ion. The properties of strong electrolytes are determined by the interaction of the central ion with the atmosphere

Answer 15

Debye – Huckel Theory of Interionic Attraction

Question 16

branch of physical chemistry that concerns with interrelations between chemical phenomena and electricity. It deals not only with the study of electrical properties of solutions of electrolytes but also shows the clear relation between chemical action and electricity in such systems

Answer 16

Electrochemistry

Question 17

Formulas needed for electrochemistry

Answer 17

1. I = Ɛ / R
2. Q = IT
3. W = ƐQ = Ɛ IT
4. P = Ɛ I = IR (I) = I2R = ƐQ/T

Question 18

the invariant current of such strength that on passage through a water solution of AgNO3 it will deposit 0.001118g. of Ag in 1 sec.

Answer 18

Int’l Ampere

Question 19

the resistance at 0℃ of a column of Hg of uniform cross section, 106.3cm. long, and containing 14. 4521g. of Hg

Answer 19

Int’l Ohm

Question 20

the potential difference required to send a current(I) of 1A though a resistance of 1 ohm

Answer 20

Int’l volt

Question 21

• the process of I passage through an electrolytic conductor with all the accompanying chemical and migratory changes

Answer 21

Electrolysis

Question 22

Faraday’s Laws of Electrolysis 1st law:

Answer 22

mass of substance liberated or deposited at an electrode is ∝ to the quantity of electricity that has passed through the electrolyte

Question 23

Faraday’s Laws of Electrolysis 2nd law:

Answer 23

masses of different substances liberated or deposited by the same quantity of electricity are proportional to the chemical equivalent of the various substance.

Question 24

Non-conductors of electricity with high resistivity

Answer 24

Dielectrics or insulators

Question 25

electrical resistance of a block of the material 1cm. in length and 1cm² in cross section

Answer 25

Specific resistivity (𝜌)

Question 26

Kinds of Electrodes

Answer 26

1. Cathode 2. Anode

Question 27

the electrode connected to the (-) side of the source of I by which electrons from this source enter the solution

Answer 27

Cathode

Question 28

the electrode connected to the (+) side of a source of I through which the electrons leave the solution to return to the source.

Answer 28

Anode

Question 29

Kinds of Ions

Answer 29

1. Anion 2. Cation

Question 30

(-) ions which migrate toward the anode

Answer 30

Anions

Question 31

(+) ions which migrate toward the cathode

Answer 31

Cations

Question 32

Points to remember about Electrolytic Conduction

Answer 32

1. It includes both solutions of strong and weak electrolytes (Example: salts of NaCl and AgNO3) 2. Its electron transfer takes place by a migration of ions both (+) and (-) toward the electrodes. 3. The current flow is always accompanied by chemical change at the electrodes

Question 33

Two Types of Conductors

Answer 33

Electronic conductor Electrolytic conductor

Question 34

conduction takes place by migration of ions towards the (+) and (-) electrodes in the presence of a solution of electrolyte

Answer 34

Electrolytic conductor

Question 35

reciprocal of the electrical resistance

Answer 35

Electrolytic conductance

Question 36

conduction takes place by direct migration of electrons through the conductor under the influence of an applied potential

Answer 36

Electronic conductor

Question 37

Resistance of electronic conductors ______ with temperature

Answer 37

increases

Question 38

resistance of electrolytic conductors _________ with increasing temperature

Answer 38

decreases

Question 39

Applications of Conductance Measurements

Answer 39

1. Solubility of Difficult to Dissolve Salts 2. Determination of the degree of ionization, ∝ of any electrolyte

Question 40

Determination of Transference Numbers

Answer 40

A. Hittorf’s Rule B. Moving Boundary method

Question 41

is the interaction of the ions of salts and the ions of water

Answer 41

Hydrolysis

Question 42

What is a demal solution?

Answer 42

A solution which contains 1g mole per cubic dm of solution at 0℃.

Question 43

For strong electrolytes, Ls

Answer 43

increases sharply with concentration

Question 44

For weak electrolytes, Ls

Answer 44

starts with lower value in dilute solutions and increases more gradually.

Question 45

At Equivalent Conductance, ꓥ

Answer 45

increases with dilution for both strong and weak electrolytes.

Question 46

∝ = ꓥ / ꓥo At infinite dilution, ∝ = 1, therefore

Answer 46

ꓥ = ꓥo

Question 47

As a result of passage of 𝐼 through a sol’n., conc’n. changes directly related to the velocities of the ions occur in the vicinity of the electrodes.

Answer 47

Hittorf’s Rule

Question 48

the motion of ions under the influence of an applied potential is observed directly rather than through the concentration changes at the electrodes.

Answer 48

Moving Boundary method

Question 49

Transference numbers of the cations for a number of electrolytes in aqueous solution are not affected by

Answer 49

I strength.