P2

Question 1

from alcohol in presence of ZnCl2 ?
1,2,3

Answer 1

R-OH (alcohol)+ HX (hydrogen halide) > (ZnCl2) R-X (alkyl halide) + H2O
in primary and 2nd alcohol catalyst such as Zncl2 is used
in 3 it reacts even in its absence

Question 2

alcohol ,sodium bromide, sulphuric acid

Answer 2

NaBr + H2SO4 > HBr + NaHSO4
HBr + R-OH > R-Br + H2O

Question 3

Why is H2SO4 not used during the reaction of OH with KI?

Answer 3

H2SO4 is a strong oxidizing agent it reacts with KI to give HI which is further oxidized to form I2 instead of forming alkyl iodide
KI + H2SO4 > KHSO4 + HI
now there r still more molecules of h2so4 left in the solution so HI being a strong reducing agent reacts with a strong oxidizing agent (H2SO4)
to give I2 instead of alkyl halide
HI + H2SO4 > I2

Question 4

instead of H2SO4 what can be used?

Answer 4

u can use H3PO4 weaker oxidizing agent

Question 5

which reaction with alcohol to form alkyl halide is more preferred?

Answer 5

R-OH +SOCl2 > R-CL + SO2 + HCL
reaction with thionyl chloride is most preferred since the by products so2 and hcl are escapable gases and so the alkyl chloride can be obtained in its pure form

Question 6

aryl halides cannot be prepared from phenols under normal condition why?

Answer 6

this is due to the partial bond character (c-o bond is highly stable) of c-o resulting from positive resonance

Question 7

on what does the no of monohalo products depend?

Answer 7

the no of monohalo products depends on the diff no of hydrogen environment prsent in the compound

Question 8

prep of aryl chlorides and bromides

Answer 8

aryl chlorides and bromides can be easily prepared by electrophilic substitution of arenes with chl2 and br2 respectively in the presence of Lewis acid catalyst Fe and Fecl3

Question 9

ortho and para product separation?

Answer 9

ortho and para ismoers can be easily seprated due to the large difference in boiling points