What is the purpose of the dilute ${\mathrm{H}}_2{\mathrm{SO}}_4$ in electrolysis of water?

Consider the electrolysis of water in dilute sodium hydroxide. Identify the half-equations occurring at the cathode and anode electrodes and the equation for the overall cell reaction.

Consider the electrolysis of water in dilute sodium hydroxide. State what would be observed at each electrode.

Consider the electrolysis of water in dilute sodium hydroxide. Deduce the ratio by volumes of any species produced.

What conditions are necessary to directly measure a standard electrode potential $\left({\mathrm{E}}^{\mathrm{o}}\right)$?

I. A half-cell with an electrode in a $1.0 \mathrm{mol} {\mathrm{dm}}^{-3}$ solution of its ions.

II. Connection to a standard hydrogen electrode.

III. A voltmeter between half-cells to measure potential difference.

Consider the following standard electrode potentials.

${\mathrm{Zn}}^{2+}\left(\mathrm{aq}\right)+2\mathrm{e}\rightleftharpoons \mathrm{Zn}\left(\mathrm{s}\right){\mathrm{E}}^{\ominus }=-0.76\mathrm{V}$

${\mathrm{Cl}}_2\left(\mathrm{g}\right)+2{\mathrm{e}}^{-}\rightleftharpoons 2\mathrm{Cl}\left(\mathrm{aq}\right){\mathrm{E}}^{\ominus }=+1.36\mathrm{V}$

${\mathrm{Mg}}^{2+}\left(\mathrm{aq}\right)+2{\mathrm{e}}^{-}\rightleftharpoons \mathrm{Mg}\left(\mathrm{s}\right){\mathrm{E}}^{\ominus }=-2.37\mathrm{V}$

What will happen when zinc powder is added to an aqueous solution of magnesium chloride?

The standard electrode potentials for two metals are given below.

${\mathrm{Al}}^{3+}\left(\mathrm{aq}\right)+3\mathrm{e}\rightleftharpoons \mathrm{Al}\left(\mathrm{s}\right){\mathrm{E}}^{\ominus }=-1.66\mathrm{V}$

${\mathrm{Ni}}^{2+}\left(\mathrm{aq}\right)+2\mathrm{e}\rightleftharpoons \mathrm{Ni}\left(\mathrm{s}\right){\mathrm{E}}^{\ominus }=-0.23\mathrm{V}$

What is the equation and cell potential for the spontaneous reaction that occurs?

How do the products compare at each electrode when aqueous $1 \mathrm{mol} {\mathrm{dm}}^3$ magnesium bromide and molten magnesium bromide are electrolysed?