Test Preparation on IIT JEE Mains Mock Test-12

If the atom/group of lowest priority is at the
bottom, simply rotate the eye in the order
of descending order of priorities and find the
direction, if the arrangement of groups is
clockwise the configuration is (R) and if it
is in anticlockwise direction then the
configuration is (S).
In case of (4) the arrangement of groups (NH2(1),
CHO(2). CH3(3) is in anticlockwise direction so
its configuration is (S).
If the atom/group of lowest priority is at the top,
rotate the molecule by 180° in the plane of paper
so as bring the atom/group of the lowest priority is
at the bottom. Then find the direction of
arrangements of atoms/groups in the order of
descending priorities as shown below.

If the atom/group of lowest priority is at the lefthand
side of horizontal end, then without changing
the position of other atoms/groups at the top of
vertical end, change the position of other
atoms/groups in the anticlockwise or clockwise
direction so as to bring the atom/group of the
lowest priority at the bottom. Then find the
direction of arrangements of atoms/groups in the rder of descending priorities
o.

Acetamide (CH3CONH2) and benzonitrile
(C6H5CN) are neutral; triethylamine
(CH3CH2)3N is basic and phenol (C6H5OH) is
acidic in nature.

IUPAC name of the compound is

The organic reaction product from the reaction of
methyl magnesium bromide and ethyl alcohol is
methane.
CH3MgBr + CH3CH2OH→CH3CH2OMgBr + CH4

Ethyl alcohol and methyl alcohol can be
distinguished by iodoform test.
CH3CH2OH + I2 + NaOH→ CHI3 (iodoform)
(givesiodoform test)
CH3OH + I2 + NaOH→ no iodoform
(does not give iodoform test)

2 CrO₄^2-+ 2H+→ Cr2O₇^2- + H2O
yellow    orange

Optically active compounds contain one or more
chiral centre(s).

Alkynes having a terminal ≡C-H group react with
NaNH2 in liquid ammonia to furnish the
corresponding sodio-derivatives.
CH3C≡C-H + NaNH2→CH3C≡C- Na+ + NH3

In Cotrell smoke precipitator, smoke is allowed to
pass through a chamber having a series of plates
charged to very high potential (20,00 – 70,000V)
when charged particles of smoke get attracted to 

the charged plates, get precipitated and removed
from smoke.