Answer
Verified
398.1k+ views
Hint: Equivalent is the quantity that combines with or replaces 1 g of hydrogen or 8 g of oxygen. And titration is a technique where a solution of known concentration is used to determine the concentration of the unknown solution.
Complete step by step solution:
Equivalent weight can be defined as the one equivalent which is the mass of a given substance which combines with or replaces a fixed quantity of another substance. It is the mass of a substance that combines with or is chemically equivalent to one gram of hydrogen or eight grams of oxygen.
The titration given in the question can be written as follows:
$2KMn{ O }_{ 4 }\quad +\quad 10FeS{ O }_{ 4 }.{ (N{ H }_{ 4 }) }_{ 2 }.6{ H }_{ 2 }O\quad +\quad 8{ H }_{ 2 }O\quad \longrightarrow \quad { K }_{ 2 }S{ O }_{ 4 }\quad +\quad 2MnS{ O }_{ 4 }\quad +\quad 5{ Fe }_{ 2 }{ (S{ O }_{ 4 }) }_{ 3 }\quad +\quad 10{ (N{ H }_{ 4 }) }_{ 2 }S{ O }_{ 4 }\quad +\quad 68{ H }_{ 2 }O$
In this reaction, Mn oxidizes Fe and gets itself reduced. The oxidation state of Mn before the reaction is +7, and after the reaction, it becomes +2.
$ K\overset { +7 }{ Mn } { O }_{ 4 }\quad \longrightarrow \quad \overset { +2 }{ Mn }$
The n-factor is the change in the oxidation state of any compound.
n-factor of Mn = Change in oxidation state of Mn = 5
The equivalent weight is molecular weight divided by the n-factor.
$Equivalent\quad weight\quad =\quad \cfrac { Molecular\quad Weight }{ n-factor }$
Substituting the values, we get,
$ Equivalent\quad weight\quad =\quad \cfrac { Molecular\quad Weight }{ 5 }$
Therefore, the equivalent weight of potassium permanganate is $\cfrac {Molecular Weight}{5}$.
So, the correct answer is “Option B”.
Note:
Students tend to understand the molecular weight and the equivalent weight of a compound as equal. But they are different from each other. Molecular weight is the sum of the weights of the individual atoms in the molecule whereas, the equivalent weight is molecular weight divided by the n-factor.
Complete step by step solution:
Equivalent weight can be defined as the one equivalent which is the mass of a given substance which combines with or replaces a fixed quantity of another substance. It is the mass of a substance that combines with or is chemically equivalent to one gram of hydrogen or eight grams of oxygen.
The titration given in the question can be written as follows:
$2KMn{ O }_{ 4 }\quad +\quad 10FeS{ O }_{ 4 }.{ (N{ H }_{ 4 }) }_{ 2 }.6{ H }_{ 2 }O\quad +\quad 8{ H }_{ 2 }O\quad \longrightarrow \quad { K }_{ 2 }S{ O }_{ 4 }\quad +\quad 2MnS{ O }_{ 4 }\quad +\quad 5{ Fe }_{ 2 }{ (S{ O }_{ 4 }) }_{ 3 }\quad +\quad 10{ (N{ H }_{ 4 }) }_{ 2 }S{ O }_{ 4 }\quad +\quad 68{ H }_{ 2 }O$
In this reaction, Mn oxidizes Fe and gets itself reduced. The oxidation state of Mn before the reaction is +7, and after the reaction, it becomes +2.
$ K\overset { +7 }{ Mn } { O }_{ 4 }\quad \longrightarrow \quad \overset { +2 }{ Mn }$
The n-factor is the change in the oxidation state of any compound.
n-factor of Mn = Change in oxidation state of Mn = 5
The equivalent weight is molecular weight divided by the n-factor.
$Equivalent\quad weight\quad =\quad \cfrac { Molecular\quad Weight }{ n-factor }$
Substituting the values, we get,
$ Equivalent\quad weight\quad =\quad \cfrac { Molecular\quad Weight }{ 5 }$
Therefore, the equivalent weight of potassium permanganate is $\cfrac {Molecular Weight}{5}$.
So, the correct answer is “Option B”.
Note:
Students tend to understand the molecular weight and the equivalent weight of a compound as equal. But they are different from each other. Molecular weight is the sum of the weights of the individual atoms in the molecule whereas, the equivalent weight is molecular weight divided by the n-factor.
Recently Updated Pages
Basicity of sulphurous acid and sulphuric acid are
Three beakers labelled as A B and C each containing 25 mL of water were taken A small amount of NaOH anhydrous CuSO4 and NaCl were added to the beakers A B and C respectively It was observed that there was an increase in the temperature of the solutions contained in beakers A and B whereas in case of beaker C the temperature of the solution falls Which one of the following statements isarecorrect i In beakers A and B exothermic process has occurred ii In beakers A and B endothermic process has occurred iii In beaker C exothermic process has occurred iv In beaker C endothermic process has occurred
What is the stopping potential when the metal with class 12 physics JEE_Main
The momentum of a photon is 2 times 10 16gm cmsec Its class 12 physics JEE_Main
How do you arrange NH4 + BF3 H2O C2H2 in increasing class 11 chemistry CBSE
Is H mCT and q mCT the same thing If so which is more class 11 chemistry CBSE
Trending doubts
Difference Between Plant Cell and Animal Cell
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
Change the following sentences into negative and interrogative class 10 english CBSE
Summary of the poem Where the Mind is Without Fear class 8 english CBSE
Give 10 examples for herbs , shrubs , climbers , creepers
Write an application to the principal requesting five class 10 english CBSE
What organs are located on the left side of your body class 11 biology CBSE
What is the z value for a 90 95 and 99 percent confidence class 11 maths CBSE