Question

Degree of ionization is equal to:
A.Total number of moles of the electrolyte present in solution.
B.Total number of moles of electrolyte dissociate into ions.
C.Number of moles dissociated/ total number of moles dissolved.
D.Total number of moles dissolved/number of moles dissociated.

Answer 1

The closer the pKa of the local anesthetic is to tissue pH, the more rapid the onset time. For a weak acid or base the pKa value will determine the degree of ionization, which is described by Henderson-Hasselbalch equations. Degree of ionization is dependent on the dissolved number of total number of moles and dissociated number of moles.

Complete step by step answer:
Strength and properties of the electrolyte are described by the degree of ionization and the dissociation constant of the electrolyte.
Degrees of ionization may be defined as a fraction of the total number of molecules of an electrolyte which dissociated into ions.
It is defined by the number of ionized molecules and number of molecules which are dissolved in water. Degrees of ionization can be represented by decimal number and percentage.
It increases with increasing temperature.
It decreases in the presence of strong electrolytes
Degree of ionization is defined as $\alpha =$ total number of moles dissolved / number of moles dissociated.

Hence, Option (D) is the correct answer.

Note: At normal dilution, the value of degree of ionization is nearly 1 for strong electrolytes, while it is very less than 1 for weak electrolytes. Degree of ionization of an electrolyte in solution increases with rise in temperature. Even degree of ionization of an electrolyte decreases in the presence of a strong electrolyte having a common ion.