Question

When 9.65 ampere current was passed for 1 hour into nitrobenzene in an acidic medium, the amount of p – aminophenol produced is?

Answer 1

We know that the faraday’s first law of electrolysis states that the mass of any substance deposited or dissolved at nay electrode during electrolysis is directly proportional to the quantity of electricity passed through the solution, wherein W is directly proportional to Q.
Where, $W = Zit$
W = amount of substance liberated or deposited
I = current passed through the cell
T = time for which the current is passed
Z = electrochemical equivalent of the substance

Complete step by step answer:
Given in the question are,
Current passed for 1 hour (which is equal to 3600 seconds) = 9.65 ampere
4 moles of electrons will reduce 1 mole of nitrobenzene to p-aminophenol or we can say the reduction of nitrobenzene to p-aminophenol requires 4 electrons per molecule of nitrobenzene.
The n- factor of the reaction = 4
Molar mass of p-aminophenol $= 109.14\dfrac{g}{{mol}}$
Equivalent weight of p-aminophenol $= \dfrac{{109}}{4}$
$W = Zit = \dfrac{{EIt}}{{96500}}$
Substituting the values in the equation, we get,
$W = \dfrac{{109 \times 9.65 \times 3600}}{{4 \times 96500}}$
Solving this, we get:
$W = 9.81g$
Mass of p – aminophenol obtained $= 9.81g$

Therefore, the amount of p-aminophenol deposited is $= 9.81g$.

Note: The electrochemical equivalence (Z) of the substance is the amount of substance that is deposited or liberated during the electrolysis by the passage of current equal to 1 faraday which is equal to 96500 coulombs per mole. The equivalent weight of an element or a compound depends upon the reaction in which that species is involved.