3. Classification of elements and periodicity in properties — Chemistry STD 11 Science — Question

Statement $I$: Tropolone is an aromatic compound and has $8 \pi$ electrons.

Statement $II$: $\pi$ electrons of $ > C = O$ group in tropolone is involved in aromaticity.

In the light of the above statements, choose the correct answer from the options given below:

Given                                                                                                   $\Delta H$

$(i)\, Fe_2O_{3(s)}+3C_{(graphite)} \to 2Fe_{(s)} + 3CO_{(g)}$         $492\, kJ/mol$

$(ii)\, FeO_{(s)}+C_{(graphite)} \to Fe_{(s)} + CO_{(g)}$                     $156\, kJ/mol$

$(iii)\, C_{(graphite)} + O_{2(g)} \to CO_{2(g)}$                                   $-393 \,kJ/mol$

$(iv)\, CO_{(g)} + \frac{1}{2}\, O_{2(g)} \to CO_{2(g)}$                            $-283\, kJ/mol$

$(I){\mkern 1mu} C{H_3}CH_2^ - {\mkern 1mu}  + {\mkern 1mu} \mathop {C{H_3}N{H_2}}\limits_{p{K_a} = 35}  \rightleftharpoons \mathop {C{H_3}C{H_3}}\limits_{p{K_a} = 50}  + C{H_3}N{H^ - }$

$(II){\mkern 1mu} {F^ - }{\mkern 1mu}  + {\mkern 1mu} \mathop {{H_2}O}\limits_{p{K_a} = 15.7}  \rightleftharpoons \mathop {HF}\limits_{p{K_a} = 3.2}  + H{O^ - }$