Among formic acid,acetic acid,propanoic acid and phenol,the strongest acid in water is

The product $(A)$ obtained is:

How will you bring about the following conversions in not more than two steps?
$(i)$ Propanone to Propene
$(ii)$ Benzoic acid to Benzaldehyde
$(iii)$ Ethanol to $3-$Hydroxybutanal
$(iv)$ Benzene to $m-$Nitroacetophenone
$(v)$ Benzaldehyde to Benzophenone
$(vi)$ Bromobenzene to $1-$Phenylethanol
$(vii)$ Benzaldehyde to $3-$Phenylpropan$-1-$ol
$(viii)$ Benzaldehyde to $\alpha-$Hydroxyphenylacetic acid
$(ix)$ Benzoic acid to $m-$Nitrobenzyl alcohol

Which of the following pairs of compounds can be differentiated by $NaHCO_3$ as well as by $NaOH$?

Choose the best sequence of reactions for the transformation given. Semicolons indicate separate reaction steps to be used in the order shown.

Match the reactions given in Column-$I$ with the appropriate reagents in Column-$II$.
| Column-$I$ (Reaction) | Column-$II$ (Reagent) |
| :--- | :--- |
| $(A)$ $2CH_3COOH \rightarrow (CH_3CO)_2O$ | $(i)$ $(I) NH_3, (II) \Delta, -H_2O$ |
| $(B)$ Phthalic acid $\rightarrow$ Phthalamide | $(ii)$ $(I) Br_2 / \text{red phosphorous}, (II) H_2O$ |
| $(C)$ $CH_3CH_2COOH \rightarrow CH_3CHBrCOOH$ | $(iii)$ $Br_2 / FeBr_3$ |
| $(D)$ Benzoic acid $\rightarrow$ $m$-Bromobenzoic acid | $(iv)$ $H^+, \Delta \text{ OR } P_2O_5, \Delta$ |