Conductance

Conductance

Aug 26, 2022, 16:45 IST

About Conductance

Conductance- specific conductance is the conductance of a conductor which is observed when it is 1 cm in length and 1 sq. cm in cross-sectional area

Substances which allow electrical current to pass through them are known as conductors or electrical conductors. On the other hand, substances which to not allow electricity to pass through them are known as non - conductors or insulators. Common examples of non - conductors are rubber, wood, paper, all non - metals except carbon (graphite), etc.

Conductors , can be divided into two types , viz (i) metallic conductors , and (ii) electrolytic conductors.

Comparison of metallic and electrolytic Conductors.Thus an electrolyte may be defined as that substance which in the form of its solution or in its fused state conducts electricity and simultaneously undergoes chemical decomposition. On the contrary substances which in the form of their solutions or in their molten (fused) state do not conduct electricity are called non - electrolytes , e.g. all organic compounds.The movement of ions gives rise to what is known as the electrolytic conduction. The latter, thus, depends on the mobility of ions and anything that inhibits the motion of ions causes resistance to current flow. Factors that influence the electrical conductivity of solutions of electrolytes include interionic attraction, solvation of ions and viscosity of solvent; these factors depend on the attraction of solute-solute, solute-solvent and solvent-solvent, respectively. The average kinetic energy of the solute ions increases as the temperature is raised and, therefore, the resistance of electrolytic conductors generally decreases (i.e., conduction increases) as the temperature is raised.

Specific Conductance

The resistance (R) of a metallic conductor is directly proportional to its length () and inversely proportional to its cross-section area (a), is Thus, specific conductance is the conductance of a conductor which is observed when it is 1 cm in length and 1 sq. cm in cross-sectional area. In other words, it is the conductance of 1 cc of the conductor.The equation (2) mentioned above is also applicable for solution an electrolyte i.e. electrolytic conductor. The specific conductance of an electrolytic solution is defined as the conductance that is observed when two electrodes each of 1 sq. cm in cross-sectional are dipped into solution at a distance of 1 cm apart. In other words, specific conductance is the conductance per c.c. solution of the electrolyte. It is denoted by the symbol (K (kappa). Sometimes Kv or Kc is also used, the subscript v or c standing for dilution or concentration, respecting, signifying that K is dilution or concentration dependent.

Equivalent Conductance

Equivalent conductance is the conducting power of all the ions produced by one g-equivalent i.e. one equivalent of an electrolyte in a given solution. The equivalent conductance my, therefore, be defined as the conductance which is observed when two sufficiently large electrodes are dipped into solution at such a distance so as to enclose in between them the entire volume of solution containing one equivalent of the electrolyte.

Molar Conductance

The recent trend is to describe electrolytic conductance in terms of molar conductance which is defined as the conductance of solution due to all the ions produced by one mole of the dissolved electrolyte in a given solution.

Find below detail detail abouts conductance with solved example