Chemistry

Organic Chemistry Fundamentals

287 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 general knowledge science & technology

what is formula for chloroform?

  1. CHCL5

  2. CH2CL2

  3. CHCL3

  4. CCL4
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Chloroform has the chemical formula CHCl3, consisting of one carbon, one hydrogen, and three chlorine atoms. CHCl5 is impossible (carbon can only bond to 4 atoms), CH2Cl2 is dichloromethane, and CCl4 is carbon tetrachloride.

Multiple choice technology programming languages

.{3,5}pentane

  1. will match "cyclopentane"

  2. will match "tri-pentane"

  3. will match "n-pentane"

  4. will match "neopentane"
Reveal answer Fill a bubble to check yourself
A,B,D Correct answer
Explanation

The regular expression .{3,5}pentane matches any string containing between 3 and 5 characters followed by "pentane". "cyclopentane" has 5 preceding characters, "tri-pentane" has 4, and "neopentane" has 3, so all three match.

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

Methyl cyanide is ______

  1. Acetonitrile

  2. Acetic acid

  3. Formic acid

  4. Acetaldehyde

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Methyl cyanide (CH3CN) is systematically known as acetonitrile, the simplest nitrile compound. Acetic acid is CH3COOH, a carboxylic acid. Formic acid is HCOOH, the simplest carboxylic acid. Acetaldehyde is CH3CHO, an aldehyde. Methyl cyanide contains the nitrile functional group (-CN), not carboxylic acid or aldehyde groups.

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

Meerwein-Ponndrof reduction is found in which of the following?

  1. Aldehydes or ketones are reduced in presence of amalgamate zinc/hydrochloric acid to form alkane.

  2. Aldehydes or ketones are reduced in presence of aluminium isopropoxide to form alcohol.

  3. Aldehydes or ketones are reduced in the presence of hydrazine to alkane.

  4. Cynide reduced in presence of stannous chloride with hydrochloric acid followed by hydrolysis yield aldehydes.

  5. Both (3) and (4) are correct
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This option is correct because when aldehydes or ketones are reduced with reagent aluminium isopropoxide it gives alcohol.

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

A hydrocarbon gas decolourises alkaline potassium permanganate and gives precipitate with ammonical silver nitrate. This gas is

  1. CH4

  2. C2H

  3. C2H2

  4. C2H6
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Acetylene (C2H2) is an alkyne with a triple bond. It decolorizes alkaline KMnO4 due to unsaturation and forms a white precipitate of silver acetylide with ammoniacal AgNO3. Methane (C2H6 is ethane, C2H4 is ethene, C2H is not a stable hydrocarbon) do not give both reactions.

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.