Molar Conductivity Formula

Mole Conductivity is the chemical phenomenon of the flow of electricity through an electrolyte solution divided by the solution’s concentration. Like some other chemical phenomena, this one also has a particular formula.

Ideally, measured conductivity is denoted as ask, and the concentration is denoted as C.

From here, the formula for the molar conductivity derives as 

Λm = k /C, or Connectivity per concentration.

From the formula, it is clear that the molar conductivity is maximum for the concentration solution.

The SI unit of Molecular conductivity is Siemens Meters squared per Mole or S m² mol-¹.

How to Determine Molar Conductivity

Determination of molar conductivity requires some formula and some results of some experiments. 

Firstly, the concentration of the solution needs to be derived, and it needs to remember that the molar conductivity is maximum for the solution of concentration.

Then it would help if you found out the conductivity of the solution as a whole. Then, when you have both the results, you can divide the conductivity with the concentration of the solution to get the molar conductivity.

These all results depend on some factors. So to get a perfect result, you need to know about all those factors as well.

Concentration Of Ions and Solutions

The molar conductivity of ionic solution depends on the concentration of the solution. So the more the concentration is, the more the conductivity will be. This is because the ions are the ones that are responsible for the conduction. So if the concentration is more, the electricity flow will also be more. Thus it will have more molar conductivity.

Types of The Solution

The molar conductivity also has a great factor known as the Type of solution. In the Type of solution where more charged ions are present, it will have more conductivity. Not only that, lighter ions are getting attracted to water molecules very easily. Once they get attached to water, it becomes heavier and less conductive, as light particles conduct electricity more efficiently.

So, an inorganic solution will be a better conductor than an organic solution. As an organic solution will have lower charged particles or ions, it will not be a great conductor as an inorganic solution. Again, though, what you have derived from the molar conductance formula, will be better with a concentrated solution.

Temperature

As the molar conductivity is maximum for the solution of concentration, the temperature is not a big factor but a significant one in the molar conductivity. Generally, ions or particles become a better conductor in warmer water. This is because, in warmer water, particles start moving faster to conduct more electricity. Ideally, for a change of 1°C temperature, the molar conductivity changes to 1.9%.

25°C is the ideal temperature to find out the molar conductivity. Of course, if the temperature is far away from this temperature, the result cannot be that reliable. But you can compensate for the temperature to get accurate results near that temperature.

Also, it would help if you remembered Kohlrausch’s law of independent migration of ions. According to this law, the sum of the cation and anion’s contribution to the electrolyte can limit the molar connectivity of an electrolyte.

Problems

As many factors affect the molar conductivity, there can be some problems while deriving, For example, within conductivity. With a bit change in the concentration or temperature, the results of an experiment can change. Not only the concentration, but if the Type of ions gets changed, you will not get the required result.

How to eliminate the problems

To get the perfect molar conductivity result, you need to concentrate on the factors affecting it. As the molar conductivity is maximum for the solution of concentration, you need to keep a proper concentration as you want to go ahead with the experiment. A proper type of solution is a must to go ahead, as the Type of solution can also decide the electricity to flow; you need the required Type. You need to decide whether you need an organic or inorganic solution. You cannot even miss the temperature factor as well. As the formula is based on everything, you need to keep all those factors in mind to eliminate the problems.

Conclusion

The molar conductivity formula is based on the solution’s concentration and conductivity. As the molar conductivity is maximum for the solution of concentration, it is required to take care of the proper concentration. Along with this, the Type of solution and temperature put a factor on the molar conductivity. So, to find out the molar conductivity of a solution, derive the total conductivity and the concentration. Both of these will lead you to the molar conductivity with the help of the formula