Chemistry

Organic Chemistry Fundamentals

237 Questions

Organic chemistry fundamentals cover the structure, properties, and reactions of carbon containing compounds. The questions explore functional groups, isomerism, homologous series, and basic reaction mechanisms. This forms the basis of general chemistry across multiple examination formats.

Functional groupsIsomerism typesHomologous seriesCycloalkanesOrganic monomers

Organic Chemistry Fundamentals Questions

Multiple choice

Which of the following sets represents meta-directing functional groups?

  1. -OH, -NR2, -CH3

  2. -NO, -SO3H, -CHO

  3. -NO2, -CN, -NR2

  4. -NO, -SO3H, -NR2

  5. -OH, -NR2, -SO3H
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A monosubstituted benzene, when treated with an electrophile, undergoes electrophilic aromatic substitution reaction. Each reaction yields a disubstituted benzene as the organic product, which can be identified using the descriptors ortho, para and meta products. Common ortho and para directing groups are: -OH, -NR2, -CH3, -NR2, etc. Common meta directing groups are: -NO, -SO3H, -CHO, -NO2, -CN, etc.

Multiple choice

Structure of ethylamine is ______

  1. Square

  2. Pyramidal

  3. Triangular

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ethylamine (CH3CH2NH2) has a pyramidal structure around the nitrogen atom due to sp3 hybridization with three bond pairs and one lone pair, similar to ammonia (NH3). Square planar geometry occurs in some d8 metal complexes. Triangular planar geometry occurs in sp2 hybridized molecules like boron trifluoride. Ethylamine's nitrogen is definitely not square or triangular planar.

Multiple choice

Which of the following conversions does not involve change in hybridization but only geometry is changed?

  1. NH3 → NH4+

    2. AlCl3 → AlCl4-

    3. H2O → H3O+

  1. Only 1

  2. 1 and 3

  3. Only 2

  4. 2 and 3

  5. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In both the cases, only geometry changes. NH3 → NH4+NH3: sp3 hybridization, trigonal pyramidal geometry NH4+: sp3 hybridization, tetrahedral geometry  H2O → H3O+H2O: sp3 hybridization, bent (V-shaped) geometryH3O+: sp3 hybridization, trigonal pyramidal geometry.

Multiple choice

The chemical formula of a particular compound represents-

  1. The size of molecule

  2. The shape of its molecule

  3. The total number of atoms in its molecule

  4. The number of different types of atoms in its molecule
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A chemical formula represents the types of atoms in a compound and their relative proportions. For example, H2O shows hydrogen and oxygen atoms in a 2:1 ratio. Option D correctly identifies that formulas indicate different atom types present.

Multiple choice

Give the structure of C6H6 compound, which represents bond and ring.

  1. It may have 2 double bonds and 5 rings.

  2. It may have 1 double bond and 1 ring.

  3. It may have 3 double bonds and 1 ring.

  4. It may have a single bond and 0 rings.

  5. It may have 2 double bonds and 1 ring.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The benzene ring consists of six coplanar carbon atoms bonded by alternating double and single bonds. DoU = 4, where C = 6, N = 0, X = 0, and H = 6. 1 DoB can equal 1 ring or 1 double bond. This corresponds to benzene containing 1 ring and 3 double bonds.

Multiple choice

Which among the following substances has carbon skeletons made up of isoprene units?

  1. Alkaloid

  2. Peptone

  3. Steroid

  4. Terpene
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Terpenes are composed of isoprene units (C5H8), which are five-carbon compounds that serve as building blocks. Monoterpenes have 2 isoprene units, sesquiterpenes have 3, and diterpenes have 4. Steroids are derived from terpenes but have a fused ring structure. Alkaloids contain nitrogen and peptones are protein derivatives.

Multiple choice

Which of the following pairs of silicates has the same general formula?

  1. Chain silicates and double chain silicates

  2. Double chain silicates and sheet silicates

  3. Sheet silicates and cyclic silicates

  4. Cyclic silicates and chain silicates

  5. Cyclic silicates and double sheet silicates
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Cyclic silicates as well as chain silicates have same general formula, i.e. (SiO3)n2n-.