The strongest $CO$ bond is present in

The $\pi-$acid ligand which uses its $d-$orbital during synergic bonding in its complex compound is:

The formula of the complex formed in the ring test for $NO_2^-$ and $NO_3^-$ is .....

Which of the following properties are exhibited by the $CN^-$ ion towards metal compounds?
$(a)$ Reducing
$(b)$ Oxidizing
$(c)$ Complexing

Given below are two statements:
Statement $I$ : $N(CH_3)_3$ and $P(CH_3)_3$ can act as ligands to form transition metal complexes.
Statement $II$: As $N$ and $P$ are from same group,the nature of bonding of $N(CH_3)_3$ and $P(CH_3)_3$ is always same with transition metals.
In the light of the above statements,choose the most appropriate answer from the options given below:

Nitrate is detected by the ring test. The brown color of the ring is due to which of the following?