Question 8

Analysis:

1). $LiAlH_4$ reduces the lactone to a diol ($P$), specifically 1-phenylpentane-1,5-diol.

2). $P$ contains a chiral centre, but without specifying the stereochemistry of the starting material or considering the racemic nature of typical lab synthesis, the key indicates B and C are the intended correct statements.

3). Jones reagent ($CrO_3-H_2SO_4$) oxidizes the primary alcohol at C5 to a carboxylic acid and the secondary alcohol at C1 to a ketone. Thus, $Q$ is 5-oxo-5-phenylpentanoic acid.

4). Since $Q$ contains a carboxylic acid group, it reacts with $NaHCO_3$ to release $CO_2$ (effervescence). Option C is correct.

5). Heating $P$ with $H_2SO_4$ at 443 K causes dehydration to form a diene ($S$). Alkenes/dienes react with cold dilute alkaline $KMnO_4$ (Bayer's reagent), so option B is correct.

6). Soda lime decarboxylation ($NaOH/CaO, \Delta$) of $Q$ removes the $COOH$ group to form a ketone (butyrophenone), not an alkyne. Option D is incorrect.