Chemistry Class 10 Chapter 11 Important MCQs Federal Board
Class 10 Chemistry notes
Organic Chemistry important MCQs
Multiple Choice Questions:
- Organic Chemistry is the study of
- Hydrocarbons
- Derivatives of hydrocarbons
- Both a and b
- None of them
Solution:
- The study of hydrocarbons and their derivatives is called organic chemistry.
- Therefore the answer is both a and b.
2.According to old concept, organic compounds can be derived from
- Living things
- Non-living things
- Both a and b
- None of them
Solution:
- In the start it was believed that organic compounds can only be derived from living organisms like plants and animals.
- Because at that time not even a single organic compound was derived from non-living source.
- Therefore the answer is living things.
3.According to new concept, organic compounds can be derived from
- Living things
- Non-living things
- Both a and b
- None of them
- Solution:
- In the start it was believed that organic compounds can only be derived from living organisms.
- But after the formation of urea (organic compound) from ammonium thiocyanate (in-organic compound and non-living) this notion was refuted.
- And a new concept was created according to which organic compounds can be derived from both living and non-living things.
- Therefore, the answer is both a and b.
4. In a laboratory first organic compound was synthesized by
- G.N Lewis
- Charles
- Fredrick Wohler
- Arrhenius
Solution:
- Fredrick Wohler synthesized urea an organic compound, first time in laboratory from ammonium thiocyanate.
- Therefore the answer is Fredrick Wohler.
5.The first organic compound synthesized in laboratory was
- Carbohydrate
- Protein
- Urea
- None of them
Solution:
- Fredrick Wohler synthesized first time an organic compound (urea) in laboratory.
- Therefore the answer is urea.
6. Urea in laboratory was synthesized from
- Organic compound
- In-organic compound
- Both a and b
- None of them
Solution:
- Urea in laboratory was synthesized from ammonium thiocyanate which is an in-organic compound e.g.
NH4CNO -> NH2-CO-NH2
- Therefore, the answer is in-organic compound.
7. The inorganic compound from which urea was synthesized in laboratory was
- Ammonium hydroxide
- Carbonate
- Ammonium cyanate
- Carbide
Solution:
- Urea in laboratory was synthesized from ammonium thiocyanate e.g.
NH4CNO -> NH2-CO-NH2
- Therefore, the answer is ammonium thiocyanate.
8. Organic compounds composed of carbon and hydrogen only are called
- Hydrocarbons
- Derivatives of hydrocarbons
- In-organic compounds
- Both a and b
Solution:
- Organic compounds, having only C and H atoms are called hydrocarbons.
- Therefore the answer is Hydrocarbons.
9. Organic compounds having at least one electronegative atom including C and H are called
- Hydrocarbons
- Derivatives of hydrocarbons
- Organic compounds
- Both b and c
Solution:
- Organic compounds having at least one electronegative atom e.g. O, N, S and F and C and H atoms also are called derivatives of hydrocarbons.
- And we know that hydrocarbons and their derivatives are called organic compounds.
- Therefore the answer is both b and c.
10.The bond most commonly present in organic compounds is
- Ionic bond
- Covalent bond
- Coordinate covalent bond
- Dipole-dipole interactions
Solution:
- Carbon is present in fourth group of periodic table.
- So, there are four electrons in its outermost electron.
- To complete its octet, carbon requires four another electrons.
- Therefore carbon will complete its octet by sharing four electrons with another atoms.
- And we know that, a bond formed by sharing of electrons between two carbon atoms is called covalent bond.
- Therefore, the answer is covalent bond.
11.In alkanes the carbon atoms are linked together by
- Single covalent bond
- Double covalent bond
- Triple covalent bond
- All of the above
Solution:
- Alkanes are those organic compounds in which only single covalent bonds are present between carbon atoms.
- Therefore, the answer is single covalent bond.
- A single covalent bond is a bond in which atoms share one pair of electrons.
12.Alkenes can be defined as compounds in which carbon atoms are linked together by at least one
- Single covalent bond
- Double covalent bond
- Triple covalent bond
- All of the above
Solution:
- Alkenes are those organic compounds in which at least one double covalent bond is present between any two carbon atoms.
- Therefore, the answer is double covalent bond.
- A double covalent bond is a bond in which atoms share two pairs of electron.
13.Alkynes can be defined as compounds in which carbon atoms are linked together by at least one
- Single covalent bond
- Double covalent bond
- Triple covalent bond
- All of the above
Solution:
- Alkynes are those organic compounds in which at least one triple covalent bond is present between any two carbon atoms.
- Therefore, the answer is triple covalent bond.
- A triple covalent bond is a bond in which atoms share three pairs of electron.
14.The organic compounds are separated from each other in term of classes on the basis of:
- Bonding present between them
- Color of the compounds
- Source of the compounds
- Functional group
Solution:
- A functional group is a single atom or a collection of atoms that describes a compound’s physical or chemical characteristics.
- It is a functional group which separates organic compounds into classes or families e.g.
- Carbonyl functional group –CO- containing organic compounds are differentiated as carbonyl family.
- Amine functional group –NH2 containing organic compounds are differentiated as amine’s family,
- Oxygen functional group –O- containing organic compounds are differentiated as ether’s family.
- Therefore, the answer is functional group.
15.Alcohols can be identified by
- –OH functional group
- –NH2 functional group
- –O- functional group
- –CO- functional group
Solution:
- Organic compounds in which at least one H atom is replaced with hydroxyl functional group –OH are called alcohols.
- Therefore, the answer is –OH functional group.
16.Amines can be identified by
- –OH functional group
- –NH2 functional group
- –O- functional group
- –CO- functional group
Solution:
- Organic compounds in which at least one H atom is replaced with amine functional group –NH2 are called amines.
- Therefore, the answer is –NH2 functional group.
17.Ethers can be identified by
- –OH functional group
- –COR functional group
- –O- functional group
- –X functional group
Solution:
- Organic compounds in which at least one H atom is replaced with oxygen functional group –O- are called ethers.
- Therefore, the answer is –O- functional group.
18.Ketones can be identified by
- –COOH functional group
- –NH2 functional group
- –COH functional group
- –CO- functional group
Solution:
- Organic compounds in which at least one H atom is replaced with carbonyl functional group –CO- are called ketones.
- Therefore, the answer is –CO- functional group.
19.Aldehydes can be identified by
- –CO- functional group
- –COH functional group
- –X functional group
- –CN functional group
Solution:
- Organic compounds in which at least one H atom is replaced with aldehyde functional group –COH are called aldehydes.
- Therefore, the answer is –COH functional group.
20.Carboxylic acids can be identified by
- –CO- functional group
- –COH functional group
- –COOH functional group
- –COOR functional group
Solution:
- Organic compounds in which at least one H atom is replaced with carboxyl functional group –COOH are called carboxylic acids.
- Therefore, the answer is –COOH functional group.
21.Esters can be identified by
- –COOH functional group
- –COOR functional group
- –CONH2 functional group
- –OH functional group
Solution:
- Organic compounds in which at least one H atom is replaced with ester functional group –COOR are called esters.
- Therefore, the answer is –COOR functional group.
22.Amides can be identified by
- –NH2 functional group
- –CONH2 functional group
- –CN functional group
- None of them
Solution:
- Organic compounds in which at least one H atom is replaced with amide functional group –CONH2 are called amides.
- Therefore, the answer is –CONH2 functional group.
23.The specialty of aromatic compounds is that they have
- Lone pair of electrons
- Alternate single and double bond
- Dissolve in every type of solvent
- Their reaction rates are very fast
Solution:
- An organic compound have alternate single and double bonds is called aromatic compound.
- Therefore, the answer is alternate single and double bond.
- The aromatic nature is very special property as it gives stability to aromatic compounds.
24.Aromatic nature gives __________ to organic compounds
- Color
- Stability
- Un-stability
- Both a and b
Solution:
- An organic compound have alternate single and double bonds is called aromatic compound.
- The aromatic nature is very special property as it gives stability to aromatic compounds.
- Therefore, the answer is stability.
25.Hydrocarbons are
- Polar in nature
- Non-polar in nature
- Both a and b
- None of them
Solution:
- The hydrocarbons have only C and H atoms and there is very small electronegativity difference between them.
- That’s why they are non-polar in nature.
- Therefore, the answer is non-polar in nature.
26.The non-polar nature of hydrocarbons is due
- High electronegativity difference between C and H
- Low electronegativity difference between C and H
- Both a and b
- None of them
Solution:
- The hydrocarbons have only C and H atoms and there is very small electronegativity difference between them.
- That’s why they are non-polar in nature.
- Therefore, the answer is low electronegativity difference between C and H.
27.Derivatives of hydrocarbons are
- Polar in nature
- Non-polar in nature
- Both a and b
- None of them
Solution:
- Derivatives of hydrocarbons contain at least one electronegative atom.
- So, there will be higher electronegativity difference between C and non-carbon atom (Electronegative atom).
- The enough electronegativity difference between C and non-carbon atom creates polarity in these compounds.
- Therefore, the answer is polar in nature.
28.The polar nature of derivatives of hydrocarbons is due to
- High electronegativity difference between C and non-carbon atom
- Low electronegativity difference between C and non-carbon atom
- Due to same electronegativity
- None of the above
Solution:
- Derivatives of hydrocarbons contain at least one electronegative atom.
- So, there will be high electronegativity difference between C and non-carbon atom (Electronegative atom).
- The enough electronegativity difference between C and non-carbon atom creates polarity in these compounds.
- Therefore, the answer is high electronegativity difference between c and non-carbon atom.
29.According to like dissolve like rule polar compounds are soluble in
- Polar solvents
- Non-polar solvents
- Both a and b
- None of them
Solution:
- There is a general rule of solubility, called like dissolve like rule.
- According to this rule polar compounds are soluble in polar solvents.
- And non-polar substances are soluble in non-polar solvents.
- Therefore, the answer is polar solvents.
30.According to like dissolve like rule non-polar compounds are soluble in
- Polar solvents
- Non-polar solvents
- Both a and b
- None of them
Solution:
- There is a general rule of solubility, called like dissolve like rule.
- According to this rule polar compounds are soluble in polar solvents.
- And non-polar substances are soluble in non-polar solvents.
- Therefore, the answer non-polar solvents.
31.Hydrocarbons (non-polar organic compounds) are soluble in
- Methanol
- Ethanol
- Benzene
- Both a and b
Solution:
- Hydrocarbons are non-polar in nature
- According to like dissolve like rule, they will dissolve in non-polar solvent like benzene, not in polar solvents like methanol and ethanol.
- Therefore, the answer is benzene.
32.Derivatives of hydrocarbons (polar organic compounds) are soluble in
- Methanol
- Ethanol
- Ether
- Both a and b
Solution:
- Derivatives of hydrocarbons are polar in nature
- According to like dissolve like rule, they will dissolve in polar solvents like methanol and ethanol, not in non-polar solvent like ether.
- Therefore, the answer is both a and b.
33.Catenation is the property, found in
- C
- H
- O
- N
Solution:
- Catenation is the self-linkage property found in carbon atom.
- Not in any other atom like, H, O and N.
- Therefore, the answer is C atom.
34.Due to catenation property carbon can form
- Long chains
- Short chains
- Un-stable chains
- None of them
Solution:
- Catenation is a self-linkage property.
- So, due to this self-linkage carbon form long chains.
- Therefore, the answer is long chains.
35.Isomerism is the phenomenon in which
- Compounds have same molecular and same structural formula
- Compounds have different molecular and different structural formula
- Compounds have same molecular but different structural formula
- Compounds have different molecular but same structural formula
Solution:
- Isomerism can be defined as the compounds having same molecular formula and different structural formula are called isomers and the phenomenon is called isomerism.
- Therefore, the answer is, compounds have same molecular formula but different structural formula.
36.Which factor is responsible for the diversity of organic compounds
- Catenation
- Isomerism
- Both a and b
- None of them
Solution:
- Catenation and isomerism are the two factors, responsible for the diversity of organic compounds.
- As in catenation through self-linkage carbon form variety of compounds.
- And in isomerism through different arrangement of atoms, carbon form variety of organic compounds.
- Therefore, the answer is both a and b.
37.In isomerism the structural formulas of the two isomers different, is due to
- Different molecular formula
- Different arrangement of atoms
- Different nature
- All of them
Solution:
- In isomerism we know that, compounds have same molecular formula but different structural formula.
- The difference in their structural formulas is due to different arrangement of atoms in a compound.
- Therefore, the answer is different arrangement of atoms.
38.Rate of reaction of organic compounds is
- High
- Slow
- Moderate
- Both a and c
Solution:
- In organic compounds the bond present between atoms is covalent in nature.
- Covalent bond is termed as non-polar and weak bond.
- That’s why reaction rates of organic compounds are slow.
- Therefore, the answer is slow.
39.Isomer of normal pentane
- Iso-pentane
- Neo-pentane
- Both a and b
- None of them
Solution:

Therefore, the answer is both a and b.
40.According to IUPAC names can be assigned to
- Alkanes
- Alkenes
- Alkynes
- All of them
Solution:
- International union of pure and applied chemistry assign names to each class of organic compounds either they are alkanes, alkenes or alkynes.
- Therefore, the answer is all of them.
41.In saturated hydrocarbons
- Single covalent bond present
- Double covalent bond present
- Triple covalent bond present
- Both b and c
Solution:
- The hydrocarbons in which all the carbon atoms are bounded together by single covalent bonds are called saturated hydrocarbons.
- Therefore, the answer is single covalent bond.
42.In unsaturated hydrocarbons
- Single covalent bond is present
- Double covalent bond is present
- Triple covalent bond is present
- Both b and c
Solution:
- Organic compounds in which at least one double or triple covalent bond is present between any of two carbon atoms, are called un-saturated hydrocarbons.
- Therefore, the answer is both b and c.
43.Alkanes are
- Saturated hydrocarbons
- Un-saturated hydrocarbons
- Both a and b
- None of the above
Solution:
- The hydrocarbons in which all the carbon atoms are bounded together by single covalent bonds are called saturated hydrocarbons.
- And alkanes are an organic compounds have only single covalent bonds, not double or triple covalent bonds.
- Therefore, the answer is saturated hydrocarbons.
44.Alkenes and alkynes both are
- Saturated hydrocarbons
- Un-saturated hydrocarbons
- Both a and b
- None of them
Solution:
- Organic compounds in which at least one double or triple covalent bond is present between any of two carbon atoms, are called un-saturated hydrocarbons.
- Alkenes are the organic compounds having at least one double covalent bond between any of two carbons.
- And alkynes are the compounds having at least one triple covalent bond between any of two carbon atoms.
- So, both alkene and alkyne are un-saturated.
- Therefore, the answer is un-saturated hydrocarbons.
45.Condensed structural formula for butane is
- CH3-CH2-CH3
- CH3-CH2-CH2-CH3
- CH3-CH2-CH2-CH2-CH3
- CH3-CH3
Solution:
- Condensed structural formula for butane is CH3-CH2-CH2-CH3.
- Therefore, the answer is b.
46.CH3-CH2-CH3 is the chemical formula for
- Ethane
- Propane
- Butane
- Pentane
Solution:
- In CH3-CH2-CH3 three carbon atoms are present.
- For three carbon atom alkane’s prefix Prop- and suffix “ane” is used.
- So, the chemical formula given above is the formula of propane.
- Therefore, the answer is b.
47.Which compound is not saturated hydrocarbon?
- CH3-CH3
- CH4
- CH3-CH=CH2
- CH3-CH2-CH3
Solution:
- The compounds in options a, b and d are saturated hydrocarbons.
- Because they have only single covalent bond between carbon atoms.
- They do not have double or triple covalent bond.
- Therefore they all are saturated hydrocarbons according to saturated hydrocarbon’s definition.
- While the compound in option c have one double covalent bond between last two carbon atoms.
- This double covalent bond is the indication of un-saturated hydrocarbons.
- Therefore the answer is c.
48.Prefix “But” stands for how many carbon atoms
- 2
- 3
- 4
- 5
Solution:
- But- is the prefix used for 4 carbon atoms.
- Therefore the answer is 4.
- The prefixes used for carbon atoms number 1 to 10 are listed in the table below.
Prefix | Number of Carbon atoms |
Meth- | 1 |
Eth- | 2 |
Prop- | 3 |
But- | 4 |
Pent- | 5 |
Hex- | 6 |
Hept- | 7 |
Oct- | 8 |
Non- | 9 |
Dec- | 10 |
49.Pitch is produced by
- Coal
- Coal tar
- Coal gas
- Petroleum
Solution:
- Pitch is a waste material left behind after fractional distillation of coal.
- This pitch is used in the construction of roads and roof of buildings.
50.In which of the following compounds, oxygen is attached to two alkyl carbon atoms?
- Alcohol
- Phenol
- Ether
- Ester
Solution:
- Ether is a derivative of a hydrocarbon in which the oxygen functional group -O- has been substituted for at least one H atom.
- Therefore, in ethers, one alkyl group will be attached to oxygen from the left and the other alkyl group from the right.
- Therefore, the answer is ether.
51.Which of the following is an alcohol?
- CH3-CH2-O-CH2-CH3
- CH3-CH2-COOH
- C6H5-OH
- CH3-CH2-OH
Solution:
- Alcohols are hydrocarbon derivatives having at least one H atom changed to an -OH group.
- One H replaceable -OH functional group is present in the molecule in option d.
- Therefore, the answer is CH3-CH2-OH.
52.Formic acid contains
- –OH
- –CO-
- –COOH
- –CHO
Solution:
- Hydrocarbon derivatives called carboxylic acids have at least one H atom changed to a -COOH functional group.
- Formic acid belongs to the family of carboxylic acids and has the functional group -COOH carboxyl.
- Therefore, the answer is –COOH.
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