Arrange the following in order of decreasing acid strength:

${\mathrm{CH}}_3\mathrm{OH},{\mathrm{H}}_2\mathrm{O},{\mathrm{C}}_6{\mathrm{H}}_5\mathrm{OH}$

Arrange the following in order of decreasing acidic strength:

${\mathrm{H}}_2\mathrm{O},{\mathrm{CH}}_3\mathrm{OH}$, butan-$1$-ol , butan -$2$-ol, and $2$-methyl propan-$2$-ol.

What products are obtained when ethyl alcohol is heated with conc. ${\mathrm{H}}_2{\mathrm{SO}}_4$ at

(i) $383 \mathrm{K}$

(ii) $413 \mathrm{K}$

(iii) $443 \mathrm{K}$