The correct order for acid strength of compounds :

CH $$ \equiv $$ CH, CH₃–C $$ \equiv $$ CH and CH₂ = CH₂ is as follows

The major product of the following reaction is

The standard electrode potential $${E^o }$$ and its temperature coefficient $$\left( {{{d{E^o }} \over {dT}}} \right)$$ for a cell are 2V and $$-$$ 5 $$ \times $$ 10^$$-$$4 VK^$$-$$1 at 300 K respectively.
The cell reaction is
Zn(s) + Cu²⁺ (aq) $$\buildrel \, \over \longrightarrow $$ Zn²⁺ (aq) + Cu(s)

The standard reaction enthalpy ($$\Delta $$_rH$${^o }$$) at 300 K in kJ mol^–1 is, [Use R = 8 JK^–1 mol^–1 and F = 96,000C mol^–1]

The metal d-orbitals that are directly facing the ligands in K₃[Co(CN)₆] are -