What is $Z$ in the following reaction sequence?
$C_6H_5NH_2$ $\xrightarrow[(i) NaNO_2 + HCl / 273 \ K]{(ii) H_3PO_2 + H_2O}$ $\xrightarrow[(iii) CO, HCl, \text{anhydrous } AlCl_3/CuCl]{} Z$

Give names of the reagents to bring about the following transformations:
$(i)$ $\text{Hexan-}1\text{-ol}$ to $\text{hexanal}$
$(ii)$ $\text{Cyclohexanol}$ to $\text{cyclohexanone}$
$(iii)$ $p\text{-Fluorotoluene}$ to $p\text{-fluorobenzaldehyde}$
$(iv)$ $\text{Ethanenitrile}$ to $\text{ethanal}$
$(v)$ $\text{Allyl alcohol}$ to $\text{propenal}$
$(vi)$ $\text{But-}2\text{-ene}$ to $\text{ethanal}$

In the following reaction sequence,identify the compound $Z$ if the starting material is toluene $(C_6H_5CH_3)$:
$C_6H_5CH_3 \xrightarrow{CrO_2Cl_2 / CS_2, H_3O^+} Z$

What is the compound formed when a mixture of calcium acetate and calcium formate is subjected to dry distillation?

Propanenitrile on reaction with ethylmagnesium iodide in the presence of dry ether gives an imine complex. This imine complex on acid hydrolysis forms:

The most suitable reagent for the conversion of $RCH_2OH \to RCHO$ is