The compound that undergoes decarboxylation most readily under mild condition is

Using the data provided, calculate the multiple bond energy (kJ mol^$$-$$1) of a C=C bond in C₂H₂. That energy is (take the bond energy of C-H bond as 350 kJ mol^$$-$$1).

$$\matrix{ \hfill {2C(s) + {H_2}(g) \to {C_2}{H_2}} & \hfill {\Delta H = 225\,kJ\,mo{l^{ - 1}}} \cr \hfill {2C(s) \to 2C(g)} & \hfill {\Delta H = 1410\,kJ\,mo{l^{ - 1}}} \cr \hfill {{H_2}(g) \to 2H(g)} & \hfill {\Delta H = 330\,kJ\,mo{l^{ - 1}}} \cr } $$

In the following reaction sequence, the compound J is an intermediate.

J(C₉H₈O₂) gives effervescence on treatment with NaHCO₃ and a positive Baeyer's test.

In the following reaction sequence, the compound J is an intermediate.

J(C₉H₈O₂) gives effervescence on treatment with NaHCO₃ and a positive Baeyer's test.

The compound K is