What is the value of the primary valence of $Co$ in $CoCl_{3}$?

Which of the following is a neutral complex?

$A$ six-coordinate complex with the formula $CrCl_3 \cdot 6H_2O$ has a green color. $A$ $0.1 \ M$ solution of the complex,when treated with an excess of $AgNO_3$,yields $28.7 \ g$ of a white precipitate. What is the formula of the complex?

According to Werner's theory,the primary valency of a central metal ion is:

The number of moles of $AgCl$ precipitate formed when an excess of $AgNO_3$ is added to one mole of $[Cr(NH_3)_4Cl_2]Cl$ is:

Consider the following complex $[Co(NH_3)_5CO_3]ClO_4$. The coordination number,oxidation number,number of $d-$ electrons,and number of unpaired $d-$ electrons on the metal are respectively: