Halides And Hydrides Of Alkali

These structures represent which particular kind of halides :

Which of the given alkylhalide would undergo racemisation when hydrolysis is done with aq. KOH?

Arrange the following in increasing order of their basic strength :
A. NH₃
B. AsNH₃
C. PH₃
D. BiH₃
E. SbH₃
Choose the correct answer from the options given below :

Mercury is not considered as transition metal however it has tendency to react with chlorine to form chlorides X and Y. X reacts with Kl to give red ppt while Y doesn't react. On the contrary, Y react with NH4OH to give a black ppt. Predict the formula of X and Y :