MCQ
The size of the species, $Pb, Pb^{2+} , Pb^{4+}$ decreases as
- A$Pb^{4+} >Pb^{2+} >Pb$
- ✓$Pb>Pb^{2+} >Pb^{4+}$
- C$Pb> Pb^{4+} > Pb^{2+}$
- D$Pb^{4+} >Pb> Pb^{2+}$
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$C _{2} H _{6} \rightarrow C _{2} H _{4}+ H _{2}$
the reaction enthalpy $\Delta_{ r } H =...........{ kJ\, mol ^{-1}}$.
(Round off to the Nearest Integer).
[Given : Bond enthalpies in $kJ$ $mol$ $^{-1}:C-C : 347, C = C : 611 ; C - H : 414, H - H : 436]$