Chapter 19, Problem 95RQ

Interpretation Introduction

Interpretation:

The time (in hours) to produce the given amount of metallic chromium by electrolytic reduction is to be determined.

Concept introduction:

According to the mole concept in terms of mass, the number of moles is the ratio of the mass of a substance to the molar mass of that substance. The formula is given as follows:

$\text{number}\text{of}\text{moles}=\frac{\text{mass}\text{of}\text{substance}}{\text{molar}\text{mass}\text{of}\text{substance}}$

Charge can be calculated by using the relation given as follows:

$Q=n\text{F}$

Here, $Q$ is the charge in coulomb $\text{(C)}$, $n$ is the number moles of electrons transferred and $\text{F}$ is the Faraday constant $\left(\text{1F = 96485}\text{.340 J/V }{\text{. mol e}}^{-}\right)$.

Electric current is defined as the rate of flow of electric charge. Electric current can be calculated by using the relation given as follows:

$I=\frac{Q}{t}$

Here, $I$ is the electric current in ampere $\text{(A)}$, $Q$ is the charge in coulomb $\text{(C)}$ and $t$ is the time for which the electron current is passed.