Question

A compound [A] gives positive iodoform test in 5 minutes. When 6.0 g of [A] is treated with sodium metal, 1120 mL of hydrogen gas is evolved at `NTP`. It is assumed that [A] contains one atom of oxygen per molecule. Further when [A] reacts with `PBr_(3)`, a compound [B] is formed which on reacting with benzene in the presence of anhydrous `AlCl_(3)` gives a compound [C]. the compound [C] is a well known industrial compound and is used in the commercial preparation of phenol.
The molar mass of compound [A] is :
A. `60.0" g mol"^(-1)`
B. `90.0" g mol"^(-1)`
C. `100.0" g mol"^(-1)`
D. `120.0" g mol"^(-1)`

Answer 1

Correct Answer - A
The data suggests that the compound [A] is an alcohol.
`underset("2 moles")(2 ROH)+2Na rarr2RONa+underset(22400 mL)(H_(2))`
22400 mL of `H_(2)` is evolved from alcohol
`=2` mol
1120 mL of `H_(2)` is evolved from alcohol
`=1120/22400xx2=0.1` mol.
Now, 0.1 mole of `ROH=` 6g
`:.` 1.0 mole of `ROH =` 60 g