In the reaction
C7H8 X Y Z
Z is
o-bromotoluene
m-bromotoluene
p-bromotoluene
3-bromo-2, 2, 6- trichlorotoluene
The molal freezing point depression constant for benzene (C6H6) is 4.90 K Kg mol-1. Selenium exists as a polymer of the type Sex. When 3.26 g of selenium is dissolved in 226 g of benzene, the observed freezing point is 0.112C lower than that of pure benzene. The molecular formula of selenium is (atomic mass of Se = 78.8 g mol-1).
Se8
Se6
Se4
Se2
For carbanion
Stability order will be
P > Q > S > R
P > R > Q > S
Q > R > S > R
S > R > Q > P
A.
P > Q > S > R
As -M and -I effect increase, stability of carbanion increases.-M- effect is possible only at ortho and para-position and -I-effect is more pronounced at ortho position.
Hence, correct order of stability is
Which of the following compounds have highest melting point?
Only I
Only II
I and II
II and III