Conductors and Non-Conductors
Substances can be classified as conductors and non-conductors based on their ability to conduct electricity.
Conductors: Substances that allow electric current to flow through them are called conductors. For example, Plastic, Wood, etc.
Non-Conductors: Non-conductors are insulators that do not allow electricity to pass through them. For example, Copper, Iron, etc.
Types of Conductors
Conductors are divided into two groups: Metallic conductors and Electrolytes.
Metallic Conductors: These conductors conduct electricity by the movement of electrons without any chemical change during the process. This type of conduction happens in solids and in the molten state.
Electrolytes: They conduct electricity by the movement of the ions in the solutions. It is present in the aqueous solution.
Distinguish between Metallic and Electrolytic Conduction
Metallic Conduction Electrolytic Conduction
The movement of electrons causes the electric current The movement of ions causes the electric current
There is no chemical reaction Ions get ionised or reduced at the electrodes
There is no transfer of matter It involves the transfer of matter in the form of ions
Follows Ohm’s law Follows Ohm’s law
Resistance increases with an increase in temperature Resistance decreases with an increase in temperature
Faraday’s law is not followed Follows Faraday’s law
Electrolytes
(a) Substances whose aqueous solutions allow the conductance of electric current and are chemically decomposed are called electrolytes.
(b) The positively charged ions furnished by the electrolyte are called cations, while the negatively charged ions furnished by the electrolyte are called anions.
Types of Electrolytes
(a) Weak electrolytes: Electrolytes that are decomposable to a very small extent in their dilute solutions are called weak electrolytes. For example, organic acids, inorganic acids and bases etc.
(b) Strong electrolytes: Electrolytes that are highly decomposable in aqueous solution and conduct electricity frequently are called electrolytes. For example, mineral acid and salts of strong acid.
Electrode
For the electric current to pass through an electrolytic conductor, the two rods or plates called electrodes are always needed. These plates are connected to the terminals of the battery to form a cell. The electrode through which the electric current flows into the electrolytic solution is called the anode, also called the positive electrode, and anions are oxidised here.
An electrode through which the electric current flows out of the electrolytic solution is called the cathode, also called the negative electrode, and cations are reduced there.
Electrolysis
Electrolysis is the process of chemical deposition of the electrolyte by passing an electric current. Electrolysis takes place in an electrolytic cell. This cell will convert the electrical energy to chemical energy.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Conductors and Non-Conductors
Substances can be classified as conductors and non-conductors based on their ability to conduct electricity.
Conductors: Substances that allow electric current to flow through them are called conductors. For example, Plastic, Wood, etc.
Non-Conductors: Non-conductors are insulators that do not allow electricity to pass through them. For example, Copper, Iron, etc.
Types of Conductors
Conductors are divided into two groups: Metallic conductors and Electrolytes.
Metallic Conductors: These conductors conduct electricity by the movement of electrons without any chemical change during the process. This type of conduction happens in solids and in the molten state.
Electrolytes: They conduct electricity by the movement of the ions in the solutions. It is present in the aqueous solution.
Distinguish between Metallic and Electrolytic Conduction
Metallic Conduction Electrolytic Conduction
The movement of electrons causes the electric current The movement of ions causes the electric current
There is no chemical reaction Ions get ionised or reduced at the electrodes
There is no transfer of matter It involves the transfer of matter in the form of ions
Follows Ohm’s law Follows Ohm’s law
Resistance increases with an increase in temperature Resistance decreases with an increase in temperature
Faraday’s law is not followed Follows Faraday’s law
Electrolytes
(a) Substances whose aqueous solutions allow the conductance of electric current and are chemically decomposed are called electrolytes.
(b) The positively charged ions furnished by the electrolyte are called cations, while the negatively charged ions furnished by the electrolyte are called anions.
Types of Electrolytes
(a) Weak electrolytes: Electrolytes that are decomposable to a very small extent in their dilute solutions are called weak electrolytes. For example, organic acids, inorganic acids and bases etc.
(b) Strong electrolytes: Electrolytes that are highly decomposable in aqueous solution and conduct electricity frequently are called electrolytes. For example, mineral acid and salts of strong acid.
Electrode
For the electric current to pass through an electrolytic conductor, the two rods or plates called electrodes are always needed. These plates are connected to the terminals of the battery to form a cell. The electrode through which the electric current flows into the electrolytic solution is called the anode, also called the positive electrode, and anions are oxidised here.
An electrode through which the electric current flows out of the electrolytic solution is called the cathode, also called the negative electrode, and cations are reduced there.
Electrolysis
Electrolysis is the process of chemical deposition of the electrolyte by passing an electric current. Electrolysis takes place in an electrolytic cell. This cell will convert the electrical energy to chemical energy.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
2. What is electrochemistry?
Electrochemistry is the part of
chemical sciences that deals with
heterogeneous electron transfer
reactions.
Applications
1) Sensor : Glucose senor, pH sensor, arsenic sensor etc
2) Energy: (a) Battery: Dry cell, lead storage cell etc
(b) Fuel cell: Methanol fuel cell
3) Electroplating
4) Wastewater treatment etc
3. In chemistry and manufacturing, electrolysis is a
technique that uses a direct electric current (DC) to drive
an otherwise non-spontaneous chemical reaction.
Faraday's law of electrolysis : The amount of substance produced at each
electrode is directly proportional to the quantity of charge flowing through the
cell.
Electrolysis
4. Problem 1: Find the charge in coulomb on 1 mole-ion of N3-.
Solution:
Charge on one ion of N3-
= 3 × 1.6 × 10-19 coulomb
Thus, charge on one mole-ion of N3-
= 3 × 1.6 10-19 × 6.02 × 1023
= 2.89 × 105 coulomb
Problem 2
How much charge is required to reduce (a) 1 mole of Al3+ to Al
and (b)1 mole of KMnO4 to Mn2+ ?
Solution:
( a ) T h e r e d u c t i o n r e a c t i o n i s
Al3+ + 3e- → Al
Thus, 3 mole of electrons are needed to reduce 1 mole of Al3+
Q = 3 × F = 3 × 96500 = 289500 coulomb
(b) The reduction is
M n 4 - + 8 H + 5 e - → M n 2 + + 4 H 2 O
1 m o l e 5 m o l e
Q = 5 × F = 5 × 96500 = 48500 coulomb
Electrolysis
5. Problem3.
How much electric charge is required to oxidise (a) 1 mole of H2O
to O2 and (b)1 mole of FeO to Fe2O3?
Solution:
(a) The oxidation reaction is
H 2 O → 1 / 2 O 2 + 2 H + + 2 e -
Q = 2 × F = 2 × 96500 =193000 coulomb
(b) The oxidation reaction is
F e O + 1 / 2 H 2 O → 1 / 2 F e 2 O 3 + H + + e -
Q = F = 96500 coulomb
Problem 4.
Exactly 0.4 faraday electric charge is passed through three electrolytic cells in series, first containing AgNO3, second CuSO4 and third
FeCl3 solution. How many gram of rach metal will be deposited assuming only cathodic reaction in each cell?
Solution:
The cathodic reactions in the cells are respectively.
Ag+ + e- → Ag
Cu2+ + 2e- → Cu
and Fe3+ + 3e- → Fe
Hence, Ag deposited = 108 × 0.4 = 43.2 g
Cu deposited = 63.5/2×0.4=12.7 g
and Fe deposited = 56/3 ×0.4=7.47 g
Electrolysis
FeCl3
1F can react with 1 mole charge
6. Problem5.
An electric current of 100 ampere is passed through a molten liquid of
sodium chloride for 5 hours. Calculate the volume of chlorine gas liberated at the
electrode at NTP.
Solution:
The reaction taking place at anode is
Cl- → 1/2Cl2 + e-
Q = I × t = 100 × 5 × 3600 = 180,0000 coulomb = 18.65 F
1F can liberate 0.5 mol Cl2 gas
Hence, 18.65F can liberate 9.32 mol Cl2 gas
Now PV= nRT,
or V = nRT/P = 9.32 mol x 22.4 L (at NTP) = 208.91 L
Electrolysis
12. • Small ions may have larger electric field.
• An ion with stronger electric field carries more solvent (water)
molecules with it when it moves through the solution.
• Small ions may have bigger Stokes radius.
a: hydrodynamic radius
(Stokes radius)
fs
fric
F
-----2r------
Ffric
Hydration sphere
r
f
6
13. The mobilities of ions
+ -
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
+
+
+
+
+ +
+
+
+
+
+
+
+ +
+
Electric field E
+ -
s
Mobility:
Drift speed s :
f
ze
s
E
E
u
s
r
ze
f
ze
u
6
+
-----2a------
S Ffric=fs
Felec=zeE
14. Relative ionic size and mobility
For different ions with the same charge such as Li+, Na+ and K+ the
electrical forces are equal, so that the drift speed and the mobility are
inversely proportional to the radius. In fact, conductivity measurements
show that ionic mobility increases from Li+ to Cs+.
Ionic mobility
solvation
15. Questions
1) Define drift velocity and Ionic mobility.
2) Show how ionic mobility of a ion is related to physical parameters such as
viscosity of medium, charge of ion and size of the ion.
3) Although K+ is larger than Li+ but ionic mobility of K+ is higher. Explain.
4) At infinite dilution, calculate molar conductance of ions of group-1
elements.
5) What is the order of ionic mobility of ions of alkaline metals?
6) Why KCl and KNO3 are used as supporting electrolytes or used in salt
bridge?
7) Why KCl is better than NaCl in reducing blood pressure?
16. Questions
8) Define hydrodynamic radius and ionic radius.
9) The Cs+ cations with z=1 and hydrodynamic radius (taken as the ion
radius plus the first hydration sphere) r=170 pm move in a solution
with viscosity of 1.0 cP (1.0╳ 10-3kg m-1s-1).
Estimate the mobility of the cation.
Mah-che@sust.edu
mahtazim@yahoo.com
17. End of lecture 2
May Allah SWT be with you and keep you safe from all evil effects and
diseases
Stay fine
Allahhafez
18. Lecture 3
What different ways ions and molecules use to move in solution?
Ions
1) Convection
2) Migration
3) Diffusion
Molecules
1) Convection
2) Diffusion
19.
20.
21. Steps of electrochemical process
(1) mass transfer
(2) adsorption-
(4) desorption
(3) Electron transfer
(5) mass transfer
22. • When we perform electrochemical experiments, we stop covection by keeping
the system ( electrochemical cell) rest such that no external force can cause any
movement of ions.
• Diffusion of ions are natural as near the electrode surface mass vacancy is
created when electrolysis is performed. Hence, often ionic mobility near the
electrode surface is strongly dependent on difussion of ions/molecules.
23. 1) If electrode is highly active then near
the electrode difusssion is dominent
near the electrode surface
Diffision Diffision
(bulk)
2) If electrode is less active then in all
cases ion moves due to migration only.
Important
24. Diffusion
For an efficient electrolysis process, near the electrode
surface concentration of ions is decreased, so ionic mobility
is highly dependent on diffision of ions.
Diffision layer
ET
ET rate mass transfer rate
25.
26. Molar conductivity
Around the diffusion layer J = sc where s= dirift velocity and c = concentration
Hence, J = sc =
RT
DF
dx
dc
c
D
s
or
dx
dc
D
sc
or
sc
dx
dc
D
J
1
,
,
Fick's first law of diffusion
27. We know that uE
s
Ionic mobility is proportional to ionic charge , hence zs
uE
E
zs
u
zD
zsl
l
zs
u
/
where, D= sl, l is the distance between two electrodes and is the
potential between two electrodes
Note that potential = RT/F, thus the above expression can be written as
RT
zFD
u
Relation between Molar conductivity and diffusion
s= drift velocity ( cm s-1)
u= ionic mobility (cm2 V-1s-1
E= potential applied per unit distance (Vcm-1)
= applied potential (V)
l= distance between electrodes (cm)
D=diffusion coefficient (cm2s-1)
z= charge number
28. Now we know that = zuF and
Combining these two equations , we get
RT
F
D
z
v
D
z
v
2
2
2
)
(
RT
zFD
u
This equation is known as Einstein- Nernst equation and explains that
(i) Molar conductivity is proportional to diffision coefficient
(ii) Molar conductivity is a function of square of charge on the ion
This equation can be written to represent molar conductivity of an electrolyte as
RT
DF
z 2
2
Important: This equation represents molar conductivity assuming that electrolytes are fully
dissociated. For weak or sparigly soluble salts, molar conductivity is valid at infinite dilution.
29. Molar conductivity: is the conductivity of one mole ion or electrolyte at infinite dilution.
Hence, one can compare conductivity at infinite dilution only. It is only applicable at infinite dilution to compare two or more
ionic species.
But at a given concentration, the specific conductivity can best explain the relative strength of conductivity.
Specific conductivity is the conductivity of ions/eelctrolytes in present in 1cm3 volume of solution
Units:
Molar conductivity- Scm2 mol-1
Specific conducttivity- Scm-1
30. Consequently, specific conductivity largely dependent on concentration of
electrolyte/ions and charge.
How specific conductivity is related to ionic mobility and concentration?
We know that = zuF (1)
(2) where is specific conductance and C is
concentration
Combining these two equations we get
or, (3)
so, k depends on charge of ions, ionic mobility and concentration
31. Both salts are sparingly soluble in water and even under saturated condition they are only slightly
dissociated. So molar conductivity calculation will not give perfect result.
Hence, we have to calculate specific conductivity.
in case of satuarated Ba(NO3)2
ksp = 4.64x10-3
Thus, s = 0.1 molL-1 = 1.0x10-4 mol cm-3,
i.e CBa2+ = 1.0x10-4 mol cm-3 CNO3-= = 2.0x10-4 mol cm-3
u (Ba2+) = 6.6x10=4 cm2V-1s-1 and u (NO3-) = 7.41x10-4 cm2V-1s-1. Now, using
the following equation specific conductivity of barium and nitrate ions could
be calculated separately
k(Ba2+) = 1.27x10-5 Scm-1 and k(NO3-) = 1.43x10-5 Scm-1
and solution conductivity is (1.27+1.43)x10-5 Scm-1 =2.70x10-5 Scm-1
32. Comparison of saturated Ba(NO3)2 and BaSO4 solutions
Similarly, in case of satuarated BaSO4
ksp = 1.08x10-10
Thus, s = 1.04x10-5 molL-1 = 1.04x10-8 mol cm-3,
i.e CBa2+ = 1.04x10-8 mol cm-3 CSO4= = 1.04x10-8 mol cm-3
u (Ba2+) = 6.6x10-4 cm2V-1s-1 and u (SO4) = 8.29x10-4 cm2V-1s-1. Now, using the
following equation specific conductivity of barium and sulphate ions could
be calculated separately
k(Ba2+) = 1.32x10-9 Scm-1 and k(SO4) = 1.67x10-9 Scm-1
and solution conductivity is (1.32+1.67)x10-9 Scm-1 =2.98x10-9 Scm-1
This means that kBa(NO3)2/kBaSO4 10,000
33. In two beakers A and B (containing 100ml water each), 0.74g
and 1.48g Ca(OH)2 was added. Which one was more
conductive? What was their pH values?
Add of salt to a fixed volume of solvent/ g
Ca(OH)2 (s) Ca2+(aq) + 2OH- (aq)
concentration
solubility, s
saturation point
saturated solution
u
n
s
a
t
u
r
a
t
e
d
Ca(OH)2 is a sparingly soluble base
34. Ca(OH)2
Add of salt to a fixed volume of solvent/ g
Ca(OH)2 (s) Ca2+(aq) + 2OH- (aq)
concentration
solubility, 0.011 M
saturation point, 0.0814 g/100 ml
saturated solution
u
n
s
a
t
u
r
a
t
e
d
solubility, 0.011 M = 0.814 g/L Ca(OH)2
or, 0.0814 g /100 ml Ca(OH)2 makes the
solution satuartaed. But we added 0.74 and
1.48 g salt.........!
A
ksp = 5.02x10-6
solubility, s= 0.011 molL-1
35. So maximum concentration of dissolved Ca(OH)2 both in A and B beakers were
same and it was 0.011 mol/L = 1.1x10-5 mol cm-3 . Hence, their conductivity and
pH were also same.
CCa2+= 1.1x10-5 mol cm-3 , and COH-= 2.2x10-5 mol cm-3 ,
uCa2+= 6.17x10-4 cm2V-1s-1, uOH- = 20.64x10-4 cm2V-1s-1, uCa2+= 2, uOH-=1
Now applying
kCa2+ =1.31x10-6 Scm-1, and kOH- =4.38x10-6 Scm-1
Total conductivity k= kOH-+kCa2+ = 5.70x10-6 Scm-1
36. pH
We found that s= 0.011 molL-1, [Ca2+] =0.011 molL-1 ,
Hence, [OH-] = 2x0.011 molL-1 = 0.022 molL-1
pOH= -log[OH-]= 1.66
pH= 14-pOH=14-1.66= 12.34 for both solutions
37.
38. Questions:
1) Write down the modes of mass transfer. Define each terms.
2) Draw an electrochemical system illustrating bulk and diffusion layer.
3) Under what condition diffusion coefficient can be used inplace of ionic mobility to
determine molar conductivity?
4) Write the basis of Fick's first law of diffusion.
5)Deduce Einstein-Nernst equation.
6) Define weak electrolyte and sparingly soluble salt.
7) Between 'molar conductivity' and 'specific conductivity', which one will you select to
know the relative conductivity of a solution? Explain.
8) Calculate molar conductivity of NaCl, Na2SO4, Ca(NO3)2 using diffusion coeifficient and
specific conductivity of 0.05 M solutions using ionic mobility. Repeat the calculation for
barium salts.
9) Write down the different steps of an electrochemical process ocuuring at an electrode
surface.
10) When we a reaction to be diffusion controlled?