Question

The molarity of $KMn{{O}_{4}}$ solution in basic medium is
A. 0.8M
B. 0.08M
C. 0.26M
D. 0.026M

Answer 1

Hint: Morality of a solution can be determined if the normality of the solution is known to us. Normality is an instrument or method to determine the concentration of a solution.

Complete answer:
$KMn{{O}_{4}}$ reacts in acidic basic and neutral media with $N{{a}_{2}}{{S}_{2}}{{O}_{3}}$ . The measurement is taken as 0.1M of $N{{a}_{2}}{{S}_{2}}{{O}_{3}}$ (100mL) and 100mL of $KMn{{O}_{4}}$.
In basic medium, Mn of $KMn{{O}_{4}}$ undergoes reduction from +7 state to +6.
mEq. Of $KMn{{O}_{4}}$=mEq. Of $N{{a}_{2}}{{S}_{2}}{{O}_{3}}$
$M\times 100\times n\,factor=M\times 100\times n\,factor$
$M\times 100\times 1=0.1\times 100\times 8$
$M=0.8M$
Hence, the molarity of is 0.8M. Molarity or molar concentration of a solution demonstrate the concentration of solute in the solution. Molarity is defined as the amount of parts of solute in unit volume of the solution.
The correct answer is (A).

Molarity is also calculated as the measured number of moles per unit volume that is per litre. The volume for the calculation of molarity must be taken in litres. The SI unit of molarity is mol /dm³. Molarity is demarcated by M.
Normality refers to the measured number of Gram equivalent of the solute per litre of the solution. Normality is marketed by N. Normality of a solution is also known as its equivalent concentration.
Molarity can also be calculated using normality and vice versa. Normality is the molarity’s multiple.
$N=M\times N$
Here n is the number of hydrogen ions in case of acidic medium and the number of Hydroxide ions in case of basic medium.

Note: Molarity should not be confused with molality. Molality refers to the measured number of solutes in terms of mass of solvent, that is, per kg of solvent.