The product of the reaction is:

The reaction sequence$(s)$ that would lead to $o$-xylene as the major product is (are)

The increasing order of the acidity of the following carboxylic acids is:

Arrange the following compounds in increasing order of their property as indicated:
$(i)$ Acetaldehyde,Acetone,Di-tert-butyl ketone,Methyl tert-butyl ketone (reactivity towards $HCN$)
$(ii)$ $CH_3CH_2CH(Br)COOH$,$CH_3CH(Br)CH_2COOH$,$(CH_3)_2CHCOOH$,$CH_3CH_2CH_2COOH$ (acid strength)
$(iii)$ Benzoic acid,$4$-Nitrobenzoic acid,$3,4$-Dinitrobenzoic acid,$4$-Methoxybenzoic acid (acid strength)

Calculate the value of $x + \text{molecular mass of } (C)$,where $x$ is the number of moles of $PhMgBr$ consumed in reaction $(a)$ and $(C)$ is the gas evolved in reaction $(b)$.
$(a)$ $3\text{-hydroxy-5-formylbenzoyl chloride} + x \ PhMgBr \xrightarrow{\text{excess}} (A)$
$(b)$ $2,5\text{-dioxocyclohexanecarboxylic acid} \xrightarrow{\Delta} (B) + (C) \uparrow$

The correct acidity order of the following compounds is: