$CH \equiv CH \mathop {\xrightarrow{Ni(CN)_2}}\limits_{Pressure} X$. Here,$X$ in the reaction is:

The $C - H$ bond length is minimum in the bond formed by

When acetylene reacts with arsenic trichloride in the presence of anhydrous aluminium chloride,it produces

An acyclic hydrocarbon $P$ with molecular formula $C_6H_{10}$ produces acetone as the only organic product through the following reaction sequence,where $Q$ is an intermediate organic compound:
$P (C_6H_{10})$ $\xrightarrow[(ii) NaBH_4/ethanol, (iii) dil. acid]{(i) dil. H_2SO_4/HgSO_4} Q$ $\xrightarrow[(ii) O_3, (iii) Zn/H_2O]{(i) conc. H_2SO_4 (catalytic amount), (-H_2O)} 2 CH_3COCH_3$
$1.$ The structure of compound $P$ is:
$(A)$ $CH_3CH_2CH_2CH_2-C \equiv C-H$
$(B)$ $H_3CH_2C-C \equiv C-CH_2CH_3$
$(C)$ $(CH_3)_2CH-C \equiv C-CH_3$
$(D)$ $(CH_3)_2CH-C \equiv C-H$
$2.$ The structure of compound $Q$ is:
$(A)$ $(CH_3)_2CH-CH(OH)-CH_2CH_3$
$(B)$ $(CH_3)_2CH-CH(OH)-CH_3$
$(C)$ $(CH_3)_2CH-CH_2CH(OH)CH_3$
$(D)$ $CH_3CH_2CH_2CH(OH)CH_2CH_3$
Identify the correct options for $1$ and $2$.

Which of the following reactions does not give an alkyne?

The reaction of acetylene with acetic acid in the presence of $Hg^{2+}$ at room temperature yields ....