Organic Chemistry – Some Basic Principles and Techniques Chapter-Wise Test 1

Correct answer Carries: 4.

Wrong Answer Carries: -1.

A compound with molecular formula \( \ce{C4H8O} \) is a functional isomer of butanal and contains a carbonyl group. What is its IUPAC name?

Butanal (\( \ce{CH3CH2CH2CHO} \)) is an aldehyde. Its functional isomer with a carbonyl is \( \ce{CH3COCH2CH3} \) (butan-2-one), a ketone with the same formula.

Butan-2-one
Butan-1-ol
2-Methylpropanal
Methyl propyl ether
1

Which functional group is present in \( \ce{CH3COCH3} \)?

\( \ce{CH3COCH3} \) (acetone) contains a carbonyl group (\( \ce{C=O} \)) attached to two alkyl groups, characteristic of ketones.

Aldehyde
Alcohol
Carboxylic acid
Ketone
4

Which carbon in \( \ce{CH3CH2CHO} \) is \( sp^2 \) hybridized?

In \( \ce{CH3CH2CHO} \) (propanal), the carbonyl carbon (\( \ce{C=O} \)) has three sigma bonds and one pi bond, making it \( sp^2 \) hybridized.

First carbon
Third carbon
Second carbon
All carbons
2

Which of the following is an electrophile?

\( \ce{SO3} \) is electron-deficient due to the electronegative oxygen atoms, making it an electrophile.

\( \ce{NH3} \)
\( \ce{OH^-} \)
\( \ce{SO3} \)
\( \ce{CH3^-} \)
3

What is the IUPAC name of \( \ce{CH3CH2C(OH)(CH3)CH3} \)?

The compound has a 3-carbon chain with two methyl groups and an -OH on the second carbon, named 2-methylbutan-2-ol (longest chain is butane).

2-Methylbutan-2-ol
3-Methylbutan-2-ol
Pentan-2-ol
2-Methylpentan-2-ol
1

Which separation technique is most suitable for a mixture of two liquids with boiling points 65°C and 95°C, where one is water-soluble and the other is not?

Differential extraction can exploit solubility differences (e.g., water vs. organic solvent), while the 30°C boiling point difference also allows simple distillation, but solubility makes extraction more specific.

Fractional distillation
Simple distillation
Differential extraction
Chromatography
3

An organic compound with molecular formula \( \ce{C5H10} \) shows geometrical isomerism but not chain isomerism with \( \ce{CH3CH2CH=CHCH3} \). What is its structure?

\( \ce{CH3CH2CH=CHCH3} \) (pent-2-ene) shows geometrical isomerism (cis/trans) due to different substituents on the double bond. It has no chain isomerism with itself, as it’s the same structure.

\( \ce{CH2=CHCH2CH2CH3} \)
\( \ce{CH3CH=CHCH2CH3} \)
\( \ce{CH3C(CH3)=CHCH3} \)
\( \ce{CH2=C(CH3)CH2CH3} \)
2

Which of the following compounds exhibits geometrical isomerism?

Geometrical isomerism occurs in alkenes with different substituents on each carbon of the double bond. \( \ce{CH3CH=CHCH3} \) (but-2-ene) can exist as cis or trans isomers.

\( \ce{CH3CH=CHCH3} \)
\( \ce{CH3CH2CH3} \)
\( \ce{CH3CH2OH} \)
\( \ce{CH3C#CH} \)
1

Which purification method is used for a liquid mixture with boiling points of 78°C and 82°C?

Fractional distillation is used for liquids with close boiling points (< 25°C difference), like 78°C and 82°C.

Simple distillation
Fractional distillation
Crystallization
Differential extraction
2

Which carbocation rearrangement is most likely to occur to increase stability in \( \ce{CH3CH2CH2CH2+} \)?

The primary carbocation \( \ce{CH3CH2CH2CH2+} \) can undergo a hydride shift to form \( \ce{CH3CH+CH2CH3} \) (secondary), which is more stable due to hyperconjugation.

Methyl shift to \( \ce{CH3C+(CH3)CH3} \)
No rearrangement possible
Hydride shift to \( \ce{CH3CH+CH2CH3} \)
Hydride shift to \( \ce{CH3CH2CH+CH3} \)
3

Performance Summary

Score:

Category Details
Total Attempts:
Total Skipped:
Total Wrong Answers:
Total Correct Answers:
Time Taken:
Average Time Taken per Question:
Accuracy:
0