On complete hydrogenation, natural rubber produces

Among [Ni(CO)₄], [NiCl₄]^2$$-$$, [Co(NH₃)₄)Cl₂]Cl, Na₃[CoF₆], Na₂O₂ and CsO₂, the total number of paramagnetic compound is

The correct statements about of the following reaction sequence is (are)

Cumene (C₉H₁₂) $$\mathrel{\mathop{\kern0pt\longrightarrow} \limits_{(ii)\,{H_3}{O^ + }}^{(i)\,{O_2}}} $$ P $$\mathrel{\mathop{\kern0pt\longrightarrow} \limits_{}^{CHC{l_3}/NaOH}} $$ Q (major) + R (minor)

Q $$\mathrel{\mathop{\kern0pt\longrightarrow} \limits_{PhC{H_2}Br}^{NaOH}} $$ S