HSC Science (General) 12th Standard Board Exam - Maharashtra State Board Important Questions for Chemistry

Draw structure of DDT.

Identify ‘A’ and ‘B’ in the following reaction :

\[\ce{CH3 - CH = CH2 ->[HBr]'A' ->[alc.KOH]'B'}\]

State and explain Markownikoff's rule with suitable example

How are the following conversions carried out?

2-methylbutan-1-ol into 2 -methylbutanoic acid.

But-1-ene on reaction with HCl in the presence of sodium peroxide yields _______.

IUPAC name of is C₆H₅ − CH₂ − C − CH₂ − CH₂ − CH₂ − CH₃ is _______

(A) 1-Phenylhexan-2-one

(B) 6-Phenylhexan-5-one

(C) 1-Benzylhexan-5-one

(D) Dodecan-5-one

How is nitromethane prepared from the following?

alkyl halide

How is nitromethane prepared from the following?

α-nitroalkene

Draw a neat, labelled energy profile diagram for SN¹ reaction mechanism.

Write the environmental effects of DDT.

Complete and rewrite the balanced chemical equations

Give balanced equations for the following reactions:

Acetic anhydride with phosphorus pentachloride.

What are racemates?

Give reason:

Reactions involving Grignard reagent must be carried out under anhydrous condition.

Give reason:

Alkyl halides are generally not prepared by free radical halogenation of alkanes.

Complete the following reaction sequence by writing the structural formulae of the organic compound 'A', 'B' and 'C'.

\[\ce{2-Bromobutane->[Alc.KOH]A->[][Br2]B->[][NaNH2]C}\]

The following will react faster by S_N1 mechanism

Name the reagent used to convert alkyl halide to ester.

Explain. Aryl halides are less reactive than alkyl halides towards nucleophilic substitution reactions.

What is dehydrohalogenation? State the rule for the formation of the preferred product of dehydrohalogenation.