If $NaOH$ is added to an aqueous solution of zinc ions,a white precipitate appears and on adding excess $NaOH$,the precipitate dissolves. In this solution,zinc exists in the

Which of the following cations will form the most stable complex with the same ligand?

$A$ solution contains $2.675 \ g$ of $CoCl_3 \cdot 6NH_3$ $(M = 267.5 \ g/mol)$. When passed through a cation exchanger,the chloride ions liberated are treated with excess $AgNO_3$ to yield $4.78 \ g$ of $AgCl$ $(M = 143.5 \ g/mol)$. What is the formula of the coordination compound?

$AgCl$ precipitate dissolves in ammonia due to the formation of

When pyridine is added to an aqueous solution of nickel sulfate followed by the addition of an aqueous solution of sodium nitrite,deep blue crystals of .......... are obtained.

Which is the incorrect observation?