When iodoform is heated with $Ag$ powder,the product formed is:

Which of the following is a homologue of ethyne?

In which reaction is the final product $Ph-C \equiv CH$?

$CaC_2 + 2D_2O \longrightarrow$ "$P$" $+ Ca(OD)_2$
In the above reaction,the product "$P$" is:

An unsaturated hydrocarbon $X$ on ozonolysis gives $A$. Compound $A$ when warmed with ammoniacal silver nitrate forms a bright silver mirror along the sides of the test tube. The unsaturated hydrocarbon $X$ is ..... .

What is the increasing order of acidity for the following substances?
$(1)$ $CH_2=CH_2$
$(2)$ $CH_3-CH_3$
$(3)$ $HC \equiv CH$
$(4)$ $NH_3$