What is the product formed when calcium carbide reacts with heavy water?

In the given reactions,find the sum of $(x + y)$.
$(1)$ $Ph-C(Br)_2-CH_3$ $\xrightarrow{xNaNH_2} (A)$ $\xrightarrow{CH_3I} Ph-C \equiv C-CH_3$
$(2)$ $CH_3-CH_2-C(Br)_2-CH_3 \xrightarrow{yNaNH_2} CH_3-C \equiv C-CH_3$
Find the value of $(x + y)$.

$HC\equiv CH + 2HOCl \rightarrow A$. What is the product $A$?

In the reaction $CH_3-C \equiv C-CH_3 \xrightarrow[(ii) H_2O/Zn]{(i) X} CH_3-CO-CO-CH_3$,what is $X$?

The reaction of $1,2$-dibromoethane with alcoholic potash yields.......

$A$ hydrocarbon with molecular formula $C_6H_6$ decolourises $Br_2$ water and gives a precipitate with ammoniacal $AgNO_3$. The hydrocarbon is: