Organic Chemistry – Some Basic Principles and Techniques

The number of sigma ( ) and pi ( ) bonds in pent-3-en-1-yne is -

1. 11 bonds and 2 bonds
2. 13 bonds and no bonds
3. 10 bonds and 3 bonds
4. 8 bonds and 5 bonds

Which of the following is correct with respect to -I effect of the substituents? (R = alkyl)

1. -NH2 < -OR < -F
2. -NR2 < -OR < -F
3. -NH2 > -OR > -F
4. -NR2 > -OR > -F

Which of the following carbocations is expected to be most stable?

1. [figure]
2. [figure]
3. [figure]
4. [figure]

Which of the following molecules represents the order of hybridisation sp2, sp2, sp, sp from left to right atoms?

1. HC C - C CH
2. CH2 = CH - C CH
3. CH2 = CH - CH = CH2
4. CH3 - CH = CH - CH3

The correct statement regarding electrophile is

1. electrophile is a negatively charged species and form a bond by accepting a pair of electrons from another electrophile
2. electrophiles are generally neutral species and can form a bond by accepting a pair of electrons from a nucleophile
3. electrophile can be either neutral or positively charged species and can form a bond by accepting a pair of electrons from a nucleophile
4. electrophile is a negatively charged species and can form a bond by accepting a pair of electrons from a nucleophile.

The IUPAC name of the compound [figure]

1. 5-formylhex-2-en-3-one
2. 5-methyl-4-oxohex-2-en-5-al
3. 3-keto-2-methylhex-5-enal
4. 3-keto-2-methylhex-4-enal

Which one is the correct order of acidity?

1. CH CH > CH3-C CH > CH2=CH2 > CH3-CH3
2. CH CH > CH2=CH2 > CH3-C CH > CH3-CH3
3. CH3-CH3 > CH2=CH2 > CH3-C CH > CH CH
4. CH2=CH2 > CH3-CH=CH2 > CH3-C CH > CH CH

For the following reactions : (A) CH3CH2CH2Br + KOH CH3CH=CH2 + KBr + H2O (B) [figure] (C) [figure] Which of the following statements is correct?

1. (A) is elimination, (B) and (C) are substitution reactions.
2. (A) is substitution, (B) and (C) are addition reactions.
3. (A) and (B) are elimination reactions and (C) is addition reaction.
4. (A) is elimination, (B) is substitution and (C) is addition reaction.

The pair of electrons in the given carbanion, CH3C C-, is present in which of the following orbitals?

1. sp2
2. sp
3. 2p
4. sp3

In which of the following molecules, atoms are coplanar?

1. [figure]
2. [figure]
3. [figure]
4. [figure]