The reaction of silver powder with chloroform produces $....$.

What are $X$ and $Y$ respectively in the following reactions?
$X + 2D_2O \rightarrow C_2D_2 + P$
$Y + 12D_2O \rightarrow 3CD_4 + Q$

The products of the following reaction $CH_3-C\equiv C-CH_2-CH_3 \xrightarrow[2. \text{Hydrolysis}]{1. O_3} ...$ are

Acetylene reacts with $HCN$ in the presence of $Ba(CN)_2$ to yield

$C_2H_2 \mathop {}$ ${\xrightarrow{{HgSO_4, H_2SO_4}}} A$ $\xrightarrow{{[O]}} B$. $B$ is

$A$ bromoalkane is reacted with the sodium salt of an alkyne to obtain $3$-octyne. What are the bromoalkane and the alkyne respectively?