Violet colour of $[Ti(H_2O)_6]Cl_3$ on heating changes to $........$

The solubility of silver bromide in hypo solution is due to the formation of

On adding an excess of $NH_3$ solution to $CuSO_4$ solution,the dark blue colour is due to the formation of which complex?

Which of the following statements is not correct?

$AgNO_3 \xrightarrow{\Delta} (W) + (X) + O_2$
$(X) + H_2O \longrightarrow HNO_2 + HNO_3$
$(W) + HNO_3 \longrightarrow Y + NO + H_2O$
$(Y) + Na_2S_2O_3(\text{excess}) \longrightarrow (Z) + NaNO_3$
Identify $(W)$ to $(Z)$.

Choose the incorrect stability order.