Which of the following changes involves transfer of 5 electrons?

Identify order of following reaction.

$$\mathrm{H}_2 \mathrm{O}_{2(\mathrm{~g})} \longrightarrow 2 \mathrm{H}_2 \mathrm{O}_{(\mathrm{l})}+\mathrm{O}_{2(\mathrm{~g})}$$

Assuming complete ionisation, arrange the following solutions in order of increasing osmotic pressure.

a) $0.5 \mathrm{~m} \mathrm{~Li}_2 \mathrm{SO}_4$

b) $\mathrm{0.5 ~m~KCl}$

c) $0.5 \mathrm{~m} \mathrm{~Al}_2\left(\mathrm{SO}_4\right)_3$

d) $0.1 \mathrm{~m~BaCl}_2$

Which isomer of $\mathrm{C}_4 \mathrm{H}_9 \mathrm{OH}$ has lower boiling point?