Chromyl chloride converts a methyl group to a chromium complex,which on acid hydrolysis gives the corresponding aldehyde. This reaction is called:

Which of the following compounds gives a ketone with a Grignard reagent?

Benzyl chloride when oxidised by $Pb(NO_3)_2$ gives

What is $(P)$ in the reaction given below?
$(P)$ $\xrightarrow[\text{(ii) } H_3O^{+}]{\text{(i) } CH_3MgBr} (R)$ $\xrightarrow[\text{(ii) } \Delta]{\text{(i) dil. } NaOH} \text{4-methylpent-3-en-2-one}$

Identify the compound $C$ in the following sequence:
$(CH_3)_2CHCH_2C \equiv N$ $\xrightarrow{HCl, H_2O} \text{compound } A$ $\xrightarrow[2. H_2O]{1. LiAlH_4} \text{compound } B$ $\xrightarrow{PCC, CH_2Cl_2} \text{compound } C$

Catalyst used in Rosenmund reduction is