## How to Calculate and Solve for Current Density | Corrosion

The image above represents current density.

To compute for current density, three essential parameters are needed and these parameters are Number of Electron Charge Present (z), Force (F) and Rate of Heterogeneous Reaction (V).

The formula for calculating current density:

j = zFV

Where:

j = Current Density
z = Number of Electron Charge Present
F = Force
V = Rate of Heterogeneous Reaction

Let’s solve an example;
Find the current density when the number of electron charge present is 6, the force is 4 and the rate of heterogeneous reaction is 8.

This implies that;

z = Number of Electron Charge Present = 6
F = Force = 4
V = Rate of Heterogeneous Reaction = 8

j = zFV
j = (6) (4) (8)
j = 192

Therefore, the current density is 192 A/m².

Calculating the Number of Electron Charge Present when the Current Density, the Force and the Rate of Heterogeneous Reaction is Given.

z = j / FV

Where;

z = Number of Electron Charge Present
j = Current Density
F = Force
V = Rate of Heterogeneous Reaction

Let’s solve an example;
Find the number of electron charge present when the current density is 40, the force is 2 and the rate of heterogeneous reaction is 4.

This implies that;

j = Current Density = 40
F = Force = 2
V = Rate of Heterogeneous Reaction = 4

z = j / FV
z = 40 / 2 x 4
z = 40 / 8
z = 5

Therefore, the number of electron charge present is 5.

## How to Calculate and Solve for Rate of Heterogeneous Reaction | Corrosion

The image above represents rate of heterogeneous reaction.

To compute for rate of heterogeneous reaction, two essential parameters are needed and these parameters are dn/dt and Amount of Material (n).

The formula for calculating rate of heterogeneous reaction:

V = dn/dt / n

Where:

V = Rate of Heterogeneous Reaction
dn/dt = dn/dt
n = Amount of Material

Let’s solve an example;
Find the rate of heterogeneous reaction when the dn/dt is 36 and the amount of material is 12.

This implies that;

dn/dt = dn/dt = 36
n = Amount of Material = 12

V = dn/dt / n
V = 24 / 12
V = 2

Therefore, the rate of heterogeneous reaction is 2.

Calculating the dn/dt when the Rate of Heterogeneous Reaction and the Amount of Material is Given.

dn/dt = V x n

Where;

dn/dt = dn/dt
V = Rate of Heterogeneous Reaction
n = Amount of Material

Let’s solve an example;
Find the dn/dt when the rate of heterogeneous reaction is 28 and the amount of material is 2.

This implies that;

V = Rate of Heterogeneous Reaction = 28
n = Amount of Material = 2

dn/dt = V x n
dn/dt = 28 x 2
dn/dt = 56

Therefore, the dn/dt is 56.

## How to Calculate and Solve for Rate of Homogeneous Reaction | Corrosion

The image above represents rate of homogeneous reaction.

To compute for rate of homogeneous reaction, two essential parameters are needed and these parameters are dn/dt and Stoichiometric Number (v).

The formula for calculating rate of homogeneous reaction:

Vr = dn/dt / v

Where:

Vr = Rate of Homogeneous Reaction
dn/dt = dn/dt
v = Stoichiometric Number

Let’s solve an example;
Find the rate of homogeneous reaction when the dn/dt is 24 and the stoichiometric number is 12.

This implies that;

dn/dt = dn/dt = 24
v = Stoichiometric Number = 12

Vr = dn/dt / v
Vr = 24 / 12
Vr = 2

Therefore, the rate of homogeneous reaction is 2.

Calculating the dn/dt when the Rate of Homogeneous Reaction and the Stoichiometric Number is Given.

dn/dt = Vr x v

Where;

dn/dt = dn/dt
Vr = Rate of Homogeneous Reaction
v = Stoichiometric Number

Let’s solve an example;
Find the dn/dt when the rate of homogeneous reaction is 18 and the stoichiometric number is 4.

This implies that;

Vr = Rate of Homogeneous Reaction = 18
v = Stoichiometric Number = 4

dn/dt = Vr x v
dn/dt = 18 x 4
dn/dt = 72

Therefore, the dn/dt is 72.

## How to Calculate and Solve for Electrode Potential | Nernst Equation | Corrosion

The image above represents electrode potential.

To compute for electrode potential, three essential parameters are needed and these parameters are Standard Electrode Potential (Eo), Number of Electrons (n) and Molar Activity (Cion).

The formula for calculating electrode potential:

E = Eo0.059/nIn(Cion)

Where:

E = Electrode Potential | Nernst Equation
Eo = Standard Electrode Potential
n = Number of Electrons
Cion = Molar Activity

Let’s solve an example;
Find the electrode potential when the standard electrode potential is 14, the number of electrons is 10 and the molar activity is 12.

This implies that;

Eo = Standard Electrode Potential = 14
n = Number of Electrons = 10
Cion = Molar Activity = 12

E = Eo0.059/nIn(Cion)
E = 14 – 0.059/10In(12)
E = 14 – (0.0059)(2.48)
E = 14 – 0.0146
E = 13.98

Therefore, the electrode potential is 13.98 V.