Conductometry and Ohm's Law Quiz

Study Notes

Conductometry deals with measuring the electrical conductance of electrolyte solutions like acids, bases, and salts
These solutions conduct electricity due to the movement of ions towards oppositely charged electrodes.
Applications of conductometry include neutralization titrations, precipitation titrations, chemical kinetics, and plant laboratories.

Ohm's Law is obeyed by metallic conductors and electrolyte solutions
It states that the current (I) flowing through a conductor is directly proportional to the potential difference (V) applied across the conductor and inversely proportional to the resistance (R) of the conductor.
The equation for Ohm's Law is: 𝐼=𝑉/𝑅
- I is the current (measured in Amperes)
- V is the potential difference (measured in Volts)
- R is the resistance (measured in Ohms)

Conductance is the ease with which current flows through a conductor or solution
It is the reciprocal of resistance.
Equation: C= 1/R
Unit is Ohm-1 or mho

The resistance of any uniform conductor is directly proportional to its length (l) and inversely proportional to its cross-sectional area (A).
Equation: R α l/A
Specific resistance (ρ) is measured when the length (l) is 1 cm and the area (A) is 1 cm². In this case, R = ρ.
Therefore, ρ = R *A / l
Unit: ohm.cm

To understand equivalent conductance, imagine a rectangular trough with opposite sides made of metallic conductors (acting as electrodes) 1 cm apart.
If 1 cm³ (1 mL) of solution containing 1 gram equivalent of an electrolyte is placed in this container, the conductivity of the solution could be measured.
Equation: λ= κ V
V is the ml of solution containing one gram equivalent of the electrolyte.
If the concentration of the solution is c g equivalent per liter, then the volume containing 1 g equivalent of the electrolyte is 1000/C.
Equation for equivalent conductance: λ= κ x 1000 / C
Unit: ohm-1 cm2 gm equi-1

This measures the conductivity of a solution based on the molar concentration of the electrolyte.

Electrolytic conductance is measured using a Wheatstone bridge.
The Wheatstone bridge is a circuit that consists of four resistors (R1, R2, R3, and Rx) and a galvanometer (G) which measures the current flow through a conductor.
The resistors are arranged in a way that allows the current flow through the circuit to be measured by the galvanometer.
The bridge is connected to a power source (S), such as a battery, and a tapping key (K) is placed in the circuit to control the flow of current.