$\text{PhOH\hspace{0.17em}}\underset{\text{NaOH}}{\overset{{\text{Me}}_{\text{2}}{\text{SO}}_{\text{4}}}{\to }}\text{\hspace{0.17em}P,}$ P is

(1) Ph–O–SO₂OMe

(2) PhOMe

(3) PhOSO₂OPh

(4) PhMe

$\stackrel{\mathrm{HBr}}{\to }\left(\mathrm{X}\right)<mspace\; width="1em"></mspace>\underset{\mathrm{acetone}}{\overset{\mathrm{NaI}}{\to }}\left(\mathrm{Y}\right)<mspace\; width="1em"></mspace>\left(\mathrm{Major}\right)$; Product (Y) is:

(1) cis-2-butene                                 

(2) trans-2-butene

(3) 1-butene                                   

(4) Iso-butene

Common oxidizing agents used in organic chemistry are;

1. Fenton's reagent

2. Osmium tetroxide

3. Acidified KMnO₄

4. All are correct

Among the following compounds the one that is most reactive towards electrophilic nitration is:
1. Benzoic acid
2. Nitrobenzene
3. Toluene
4. Benzene

Which among the following reagents can be used for the test of carbonyl group in laboratory?

1. $N{H}_{2}OH$

2. $N{H}_{2}N{H}_2$

3. $NaS{O}_{3}H$

4. $2,4-DNPH$