Question

When 9.65 ampere of current was passed for 1.0 hour into nitrobenzene in acidic medium, the amount of p-aminophenol produced is:
A. 109.0 g
B. 98.1 g
C. 9.81 g
D. 10.9 g

Answer 1

Hint: A mole of a substance or particle can be defined as containing exactly $6.022\times {{10}^{23}}$particles which may be atoms, molecules or ions where $6.022\times {{10}^{23}}$is known as the Avogadro’s number.

Complete answer:
9.65 ampere of current was passed for 1 hour or we can say for 3600 seconds.
Number of moles of electrons passed can be calculated by the formula = $109.14\times 0.09=9.81g$ , Where I = current passed which is 9.65 ampere given, t is time taken i.e. 3600 seconds and F is faraday constant having the value 96500. Now by putting all the values in the formula we get
Number of moles = 0.36 moles
4 moles of electrons will reduce 1 mole of nitrobenzene to p-aminophenol
0.36 moles of electrons will reduce $\frac{0.36}{4}=0.09$moles of nitrobenzene to p-aminophenol
Molar mass of p-aminophenol is 109.14 g/mol
We know that number of moles will be calculated by given mass dividing by molar mass here mass will be calculated by number of moles into molar mass which will be
$109.14\times 0.09=9.81g$

This suggests that option C is the correct answer.

Note:
Mole is generally represented by the symbol mol. It is generally described as the unit of measurement for amount of substance in SI where SI stands for International System of units. It is defined on the basis of Avogadro’s number.