Q. 9.14 - An Introduction to General, Organic, and Biological Chemistry

Question

Classify the solute represented in each of the following equations as a strong, weak, or nonelectrolyte:

a. ${\mathrm{CH}}_4\mathrm{O}\left(l\right)\stackrel{{\mathrm{H}}_2\mathrm{O}}{⟶} {\mathrm{CH}}_4\mathrm{O}\left(aq\right)$

b. ${\mathrm{MgCl}}_2\left(s\right)\stackrel{{\mathrm{H}}_2\mathrm{O}}{⟶}{\mathrm{Mg}}^{2+}\left(aq\right)+2{\mathrm{Cl}}^{-}\left(aq\right)$

c. $\mathrm{HClO}\left(aq\right)\stackrel{{\mathrm{H}}_2\mathrm{O}}{\rightleftarrows }{\mathrm{H}}^{+}\left(aq\right)+{\mathrm{ClO}}^{-}\left(aq\right)$

Step-by-Step Solution

Answer

(part a) The following equation,

${\mathrm{CH}}_4\mathrm{O}\left(l\right)\stackrel{{\mathrm{H}}_2\mathrm{O}}{⟶} {\mathrm{CH}}_4\mathrm{O}\left(aq\right)$ is a nonelectrolyte.

(part b) The following equation,

${\mathrm{MgCl}}_2\left(s\right)\stackrel{{\mathrm{H}}_2\mathrm{O}}{⟶}{\mathrm{Mg}}^{2+}\left(aq\right)+2{\mathrm{Cl}}^{-}\left(aq\right)$ is a strong electrolyte.

(part c) The following equation,

$\mathrm{HClO}\left(aq\right)\stackrel{{\mathrm{H}}_2\mathrm{O}}{\rightleftarrows }{\mathrm{H}}^{+}\left(aq\right)+{\mathrm{ClO}}^{-}\left(aq\right)$ is a weak electrolyte.

Step1: Introduction (part a).

Strong electrolyte: A material that freely ionized particles entirely or nearly wholly once subsumed or melted and is an excellent electrical conductor.

Weak electrolyte: A substance that slowly and incompetently oxidizes once submerged or begins to melt and conducts less electricity.

Nonelectrolyte: A substance that, when disintegrated or melted, doesn't really polarize but does not conduct electricity.

Step2: Given Information (part a).

${\mathrm{CH}}_4\mathrm{O}\left(l\right)\stackrel{{\mathrm{H}}_2\mathrm{O}}{⟶} {\mathrm{CH}}_4\mathrm{O}\left(aq\right)$

Step3: Explanation (part a).

When hydrated, $C{H}_{4}O$ does not ionize. As a necessary consequence, it is a nonelectrolyte.

Step4: Given Information (part b).

${\mathrm{MgCl}}_2\left(s\right)\stackrel{{\mathrm{H}}_2\mathrm{O}}{⟶}{\mathrm{Mg}}^{2+}\left(aq\right)+2{\mathrm{Cl}}^{-}\left(aq\right)$

Step5: Explanation (part b).

$MgC{l}_2$ completely ionized particles in water, forming $M{g}^{2+}$ and $C{l}^{-}$ ions. As more than just a result, it is a strong electrolyte.

Step6: Given Information (part c).

$\mathrm{HClO}\left(aq\right)\stackrel{{\mathrm{H}}_2\mathrm{O}}{\rightleftarrows }{\mathrm{H}}^{+}\left(aq\right)+{\mathrm{ClO}}^{-}\left(aq\right)$

Step7: Explanation (part c).

Incomplete ionization of $HClO$ results in the formation of $H^{+}$ and $C{l}^{-}$ ions.

Hence, it is a weak electrolyte.