Why vanadium pentoxide is considered as a better catalyst than platinised asbestos?

Complete the following equation:

$\mathrm{Cu} + {\mathrm{H}}_2{\mathrm{SO}}_4(\mathrm{Conc}.) \to$

Complete the following equation:

${\mathrm{H}}_2\mathrm{S} + {\mathrm{H}}_2{\mathrm{SO}}_{4 }\to$

Complete the following equation:

$\mathrm{S} + {\mathrm{H}}_2{\mathrm{SO}}_4 (\mathrm{conc}.) \to$

Complete the following equation:

${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}\stackrel{\mathrm{Conc}.{\mathrm{H}}_2{\mathrm{SO}}_4}{\to }$

Complete the following equation:

${\left(\mathrm{COOH}\right)}_2\stackrel{\mathrm{Conc}.{\mathrm{H}}_2{\mathrm{SO}}_4}{\to }$