Using values from Table 19.2, calculate the ionic mobilitics...

Using values from Table $19.2,$ calculate the ionic mobilitics of (a) $\mathrm{Ca}^{2+},(\mathrm{b})[\mathrm{OH}]^{-},(\mathrm{c})\left[\mathrm{SO}_{4}\right]^{2-}$
(d) $\left[\mathrm{NH}_{4}\right]^{+}$ and (c) $\mathrm{I}^{-}$.

Key Concepts

Ionic Mobility

Ionic mobility measures how fast an ion moves through a medium when subjected to an electric field. It is typically defined as the drift velocity per unit electric field and plays a crucial role in understanding the transport properties of ions in solutions. This concept is central to studies in electrochemistry and physical chemistry, as it underpins the behavior of electrolytes in various applications, from batteries to biological systems.

Electrolytic Conductivity

Electrolytic conductivity relates to the overall ability of an electrolyte solution to conduct electricity, which results from the movement of its constituent ions. Each ion contributes to the total conductivity proportional to its mobility and concentration. Understanding conductivity helps in deducing individual ionic mobilities using measured or tabulated conductivity data.

Kohlrausch's Law of Independent Migration

Kohlrausch's Law states that at infinite dilution, each type of ion contributes independently to the overall conductivity of an electrolyte. This principle allows for the separation of the conductivity contributions of individual ions, making it possible to calculate their respective mobilities from experimental data and tabulated values.

Impact of Ion Size and Hydration

The size of an ion and its associated hydration shell critically affect its mobility. Generally, smaller ions with lighter hydration shells move faster under an electric field, whereas larger ions or those with more extensive solvation structures experience greater friction and thus lower mobility. This concept is essential when comparing mobilities of different ions, such as cations and anions, in solution.

Transcript

00:01 Okay, so this question asks us using the molar conductivity to calculate the mobility of irons.

00:12 So let's first write down the expression of the mobility of the irons.

00:19 The expression is the mobility of the irons equal to the molar conductivity.

00:28 At infinite low concentration over the charge that iron carries times the faradic constant, which the faradic constant is 9 -6485.

00:51 And if you know this equation, then the question becomes very easy.

00:56 So let's first look at the calcium, right? so the mobility of the calcium then equals to the molar conductivity of the calcium at infinitely low concentration over the charge the calcium carries times the ferocity constant.

01:25 So the motor conductivity of the calcium can be found in the, book, which is 1 .189 times 10 to minus 2, right? and the charge that the calcium carries is 2.

01:47 So over 2 times the 4d constant, 9, 6, 485.

01:57 And using your calculator, you can get the answer.

02:00 The final answer is 6 .162 times 10 to minus 8.

02:09 And you can add the unit yourself.

02:14 And the second iron is hydroxide, oh -h -minors, right? so let's write on again equals to the motor conductivity of oh -minors over the charge and the far -de -constant.

02:41 And check the book that the motor conductivity adds infinitely dilute solution of the oh -miners is 1 .98 times 10 to minus 2.

02:56 And over the charge, the oh -minus carries only one charge, right? so it's 1 times the far -de -constance...

Please give Ace some feedback