Distinguish between the following pairs:
a. (I)

Explanation

a. (II) is unsaturated alcohol (allyl alcohol). When `Br_(2)//CCI_(4)` solution is added to it, orange colour of `Br_(2)//CCI_(4)` disappears. However, (I) (propyl alcohol) does not react with `Br_(2)//CCI_(4)` and orange colour persists.
b. (I) (cyclopentanol) dissolves is conc. `H_(2)SO_(4)` and forms one layer, while (II) (cyclopentyl chloride) does not dissolve in conc. `H_(2)SO_(4)` and two distinct layers appear.
c. (I) (benzyl alcohol) `(1^(@) ROH)` is oxidised by acid `Cr_(2)O_(7)^(2-)` and orange of `Cr_(2)O_(7)^(2-)` changes to green `(Cr^(3+))`, whereas (II) (benzyl methyl ether) does not react.
d. (I) (ethanol) gives iodoform test due to the presence of `(CH_(3)---CH---OH)` group, whereas (II) (propanol) does not give this test. Add `(I_(2) + NaOH)` until the colour of `I_(2)` colour persists in both (I) and (II). A pale yellow precipitate of `CHI_(3)` appears in (I) but not in (II).
e. (II) (butanol, `1^(@)ROH`) is oxidised by acid `Cr_(2)O_(7)^(2-)` and orange colour of `Cr_(2)O_(7)^(2-)` changes to green `(Cr^(3+))`, whereas (I) (t-butanol, `3^(@) ROH`) is unreactive.