Heating a mixture of silver powder and $CHCl_3$ yields which compound?

An organic compound $X$ with molecular formula $C_6H_{10}$,when treated with $HBr$,forms a $gem$-dibromide. The compound $X$ upon warming with $HgSO_4$ and dil. $H_2SO_4$,produces a ketone,which gives a positive iodoform test. The compound $X$ is

Write the following reactions:
$1$. Complete combustion of ethyne in the presence of air.
$2$. Reaction of propyne with alkaline $KMnO_4$.

The reaction $Ph-C \equiv CH \xrightarrow[{(2)\,H_2O_2/OH^{-}}]{{(1)\,BH_3.THF}}$ Product; the product is

Metallic sodium does not react normally with:

Which of the following has acidic hydrogen?