The major organic compound formed by the reaction of 1, 1, 1 - trichloroethane with silver powder is:

We have to find what happens when $$\text{1,1,1-trichloroethane}$$, whose condensed formula is $$CH_3CCl_3$$, is treated with finely divided silver metal. Silver in the zero-valent state is a strong reducing agent that removes halogen atoms as silver halide, $$AgCl$$. Whenever all the halogen atoms that are attached to the same carbon (a geminal arrangement) are removed in this way, the carbon momentarily attains a divalent “carbene” state, which then couples with another such species. The overall result is the formation of a carbon-carbon triple bond.

First, write the reduction of one molecule of the trihalide by three atoms of silver.

$$CH_3CCl_3 + 3\,Ag \;\rightarrow\; CH_3C: \;+\; 3\,AgCl$$

In this equation $$CH_3C:$$ represents the carbene (a divalent carbon bearing only six electrons). Such a highly reactive species never stays free for long; two of them immediately combine by forming a new carbon-carbon bond. That coupling step is

$$2\,CH_3C: \;\rightarrow\; CH_3C \equiv CCH_3$$

Combining the two half-steps for two starting molecules gives the overall stoichiometric equation

$$2\,CH_3CCl_3 + 6\,Ag \;\rightarrow\; CH_3C \equiv CCH_3 + 6\,AgCl$$

The product $$CH_3C \equiv CCH_3$$ is 2-butyne, an alkyne containing four carbon atoms with the triple bond between the second and third carbons (counting from either end).

No alkene can appear because removal of all three halogens from a geminal trihalide forces the carbon to use the remaining valence electrons to make a triple bond after coupling. Therefore the major organic compound is the alkyne 2-butyne.

Hence, the correct answer is Option 3.