21658.In the following sequence of reactions, the alkene affords the compound B
CH3CH = CHCH3 $\xrightarrow{\;O_3\;}$ A $\underset{Zn}{ \xrightarrow{\;H_2O\;}}$ B
The compound B is
CH3CH2CHO
CH3COCH3
CH3CH2COCH3
CH3CHO
21659.Identify B and D in the following sequence of reactions.
Ethanol and alcoholic KOH
Methanol and bromoethane
Ethyl hydrogen sulphate and alcoholic KOH
Ethyl hydrogen sulphate and aqueous KOH
21660.Some meta–directing substituents in aromatic substitution aregiven. Which one is most deactivating?
–C≡N
–SO3H
–COOH
–NO2
21661.Ethyl benzene CANNOT be prepared by ______.
Clemmensen reduction
Wurtz reaction
Wurtz–Fittig reaction
Friedel–Crafts reaction
21662.Ozonolysis of an organic compound 'A' produces acetone and propionaldehyde in equimolar mixture. Identify 'A' from the following compounds
1 – Pentene
2 – Methyl – 1 – pentene
2 – Methyl – 2 – pentene
2 – Pentene
21664.Which one of these is NOT TRUE for benzene?
Heat of hydrogenation of benzene is less than the theoretical value
There are three carbon–carbon single bonds and three carbon–carbon double bonds
It forms only one type of monosubstituted product
The bond angle between carbon–carbon bonds is 120°
21665.A dibromo derivative of an alkane reacts with sodium metal to form an alicyclic hydrocarbon. The derivative is ______.
2, 2–dibromobutane
1, 1–dibromopropane
1, 4–dibromobutane
1, 2–dibromoethane
21666.One mole of a symmetrical alkene on ozonolysis gives two moles of an aldehyde having a molecular mass of 44 u. The alkene is
Ethane
Propene
1–butene
2–butene
21667.Compound which gives acetone on ozonolysis :
C6H5CH=CH2
(CH3)2C=C(CH3)2
CH3—CH=CH—CH3
CH3CH=CH2
21670.Phenyl magnesium bromide reacts with methanol to give
a mixture of anisole and Mg(OH)Br
a mixture of benzene and Mg(OMe)Br
a mixture of toluene and Mg(OH)Br
a mixture of phenol and Mg(Me)Br
21672.Cyclohexene on ozonolysis followed by reaction with zinc dust and water gives compound E. Compound E on further treatment with aqueous KOH yields compound F. Compound F is
Option (A)
Option (B)
Option (C)
Option (D)
21673.Reaction of one molecule of HBr with one molecule of 1, 3–butadiene at 40°C gives predominantly
3–bromobutene under kinetically controlled conditions
1–bromo–2–butene under thermodynamically controlled conditions
3–bromobutene under thermodynamically controlled conditions
1–bromo–2–butene under kinetically controlled conditions
21674.A gas decolourised by KMnO4 solution but gives no precipitate with ammoniacal cuprous chloride is
Ethane
Methane
Ethene
Acetylene
21676.Correct statement about 1, 3–dibutene :
forms polymer
reacts with HBr
conjugated double bonds are present
all of the above
21677.Ozonolysis of an organic compound gives formaldehyde as one of the products. This confirms the presence of
A vinyl group
Two ethylenic double bonds
An acetylenic triple bond
An isopropyl group