Deduce the structural fomula of a compound A `(C_6H_(10))` which shows the following reactions:
i. Adds 2 mol of `H_2` to form 2-methyl pentate.
ii. Reacts with aqueous `H_2SO_4+HgSO_4` solution to give a carbonyl compound.
iii. Does not react with ammoniacal `AgNO_3` solution.

Explanation

DU in (A) `(C_6H_(10))=((2xx6+2)-10)/(2)=2^@`
Reaction with `H_2SO_4+HgSO_4implies(C-=C)` bond Does not react with `[Ag(NH_3)_2]^(o+)implies` Internal alkyne

Location of `(C-=C)` bond: It should be at `(C^3-=C^4)` because `(C^4-=C^5)` is terminal alkyne, at `(C^2-=C^3)`, it is not possible because valency of carbon at `C^2` becomes 5, `C^1-=C^2)` is again a terminal alkyne and also the valency of C at `C^2` becomes 5.
Structure of A:

Attack of `overset(ө)OH` is predominant at `C-3` because positive charge on `C-3` is more stabilised due to `+I` effect of isopropyl group.