Assign oxidation number to the underlined element in the following species:

${\mathrm{H}}_2{\underline{\mathrm{S}}}_2{\mathrm{O}}_7$

Assign oxidation number to the underlined element in the following species:

$\mathrm{KAl}{\left(\underline{\mathrm{S}}{\mathrm{O}}_4\right)}_2.12{\mathrm{H}}_2\mathrm{O}$

What is the oxidation number of the underlined element and how do you rationalise your result?
$\mathrm{K}{\underset{\_}{\mathrm{I}}}_3$

What is the oxidation number of the underlined element and how do you rationalize your result?

${\mathrm{H}}_2{\underset{\_}{\mathrm{S}}}_4{\mathrm{O}}_6$

What is the oxidation number of the underlined element and how do you rationalise your result?

${\underset{\_}{\mathrm{Fe}}}_3{\mathrm{O}}_4$

What is the oxidation number of the underlined element and how do you rationalise your result?

$\underset{\_}{\mathrm{C}}{\mathrm{H}}_3\underset{\_}{\mathrm{C}}{\mathrm{H}}_2\mathrm{OH}$

Justify that the following reaction is a redox reaction:

$\mathrm{CuO}\left(\mathrm{s}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)\to \mathrm{Cu}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)$

Justify that the following reaction is a redox reaction:

${\mathrm{Fe}}_2{\mathrm{O}}_3\left(\mathrm{s}\right)+3\mathrm{CO}\left(\mathrm{g}\right)\to 2\mathrm{Fe}\left(\mathrm{s}\right)+3{\mathrm{CO}}_2\left(\mathrm{g}\right)$