Which of the following sequences represents the correct order of decreasing acidity?

All of the following compounds react with ethylmagnesium bromide $(CH_3CH_2MgBr)$. Alcohols are formed from three of the compounds. Which one does not give an alcohol?

Give the reactions of benzoic acid $(C_6H_5COOH)$ with the following:
$(i)$ Sodium metal
$(ii)$ Solution of sodium hydroxide $(NaOH)$
$(iii)$ Solution of sodium bicarbonate $(NaHCO_3)$
$(iv)$ $P_2O_5$ or conc. $H_2SO_4$ $+$ heat
$(v)$ $PCl_5$
$(vi)$ $PCl_3$
$(vii)$ $SOCl_2$
$(viii)$ $NH_3$ $+$ high temperature
$(ix)$ $LiAlH_4$ / ether or $B_2H_6$
$(x)$ Sodalime $(NaOH + CaO)$ $+$ heat
$(xi)$ Conc. $HNO_3$ $+$ conc. $H_2SO_4$ $+$ heat
$(xii)$ $Br_2 + FeBr_3$
$(xiii)$ Oleum $(H_2SO_4 + SO_3)$ $+$ heat

Which of the following reagents will convert propanoic acid into propan$-1-$ol?

$RCOOH$ on treatment with $PCl_5$ and $KCN$,is subjected to hydrolysis followed by Clemmensen's reduction,the product obtained is

Arrange these carboxylic acids in decreasing order of ease of esterification with $CH_3OH/H^{+}$:
$(I)$ $CH_3-CH(CH_3)-COOH$
$(II)$ $CH_3-CH(CH_3)-CH_2-COOH$
$(III)$ $CH_3-C(CH_3)_2-COOH$
$(IV)$ $(CH_3-CH_2)_3C-COOH$