To solve the problem, we analyze the fluorination reaction of phosphorus pentachloride (PCl5) in a polar organic solvent.
Fluorination of PCl5:
When PCl5 reacts with fluorine or a fluorinating agent in polar organic solvents, it often forms ionic species due to ligand exchange and formation of complex ions.
Known species formed:
- The cation [PCl4]+ (tetrachlorophosphonium ion)
- The anion [PF6]- (hexafluorophosphate ion)
These ions result from partial substitution of chlorine by fluorine in PCl5 and subsequent complex formation.
Therefore, the species formed are:
\[
[PCl_4]^+ [PF_6]^-
\]
Final Answer:
\[
\boxed{\text{[PCl}_4]^+ \text{[PF}_6]^-\ \text{and not the other species}}
\]
which corresponds to the second option:
[PCl4]+[PCl4F2]- and [PCl4]+[PF6]-
Let $ S $ denote the locus of the point of intersection of the pair of lines $$ 4x - 3y = 12\alpha,\quad 4\alpha x + 3\alpha y = 12, $$ where $ \alpha $ varies over the set of non-zero real numbers. Let $ T $ be the tangent to $ S $ passing through the points $ (p, 0) $ and $ (0, q) $, $ q > 0 $, and parallel to the line $ 4x - \frac{3}{\sqrt{2}} y = 0 $.
Then the value of $ pq $ is