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Class 10 Chemistry Chapter 21 Organic Chemistry Test 2
Grade 10 Chemistry chapter 21 Organic Chemistry Test 2
Prepare for the Punjab Board Class 10 Chemistry Examination 2027 with Chapter 21: Organic Chemistry – Class Test No. 2. This full chapter test includes textbook exercise questions and is designed to help students revise important concepts, assess their understanding, and improve their exam preparation. Based on the new Class 10 Chemistry syllabus issued by PECTAA Punjab, this test is part of our comprehensive Punjab Board 2027 Model Papers, Full Unit Model Papers, and Chapter-Wise Test Series. Practice board-standard questions and strengthen your preparation for the 10th Class annual examinations with our updated Chemistry test series.
ChemistryChapter-21 (Objective)Class Test-2
1. Carbon atoms are bonded by in organic compounds(Q-2)
(a) ionic(b) covalent(c) metallic(d) coordinate covalent
2. General formula of alicyclic compound is(Q-7)
(a) CnH2n-2(b) CnH2n(c) CnH2n+1(d) CnH2n+2
3. Condensed formula of ethyne is:(Q-13)
(a) CH2–CH3(b) CH2=CH2(c) CH≡CH(d) CH3–CH3
4. General formula of alcohol is(Q-19)
(a) CnH2n-2(b) CnH2n+1OH(c) CnH2n(d) CnH2n+1COOH
5. How many structural isomers of butane have(Q-22)
(a) 2(b) 3(c) 4(d) 5
6. Write functional group of alcohol is(Q-26)
(a) –OH(b) –CHO(c) –COOH(d) Double bond
7. According to IUPAC Nomenclature entire name of organic compound has Parts(Q-31)
(a) 2(b) 3(c) 4(d) 5
8. Alkene contain bond(Q-35)
(a) single(b) double(c) triple(d) closing chain
9. Carboxylic acid are also called(Q-37)
(a) Ether(b) Ester(c) Fatty acid(d) Mineral acid
10. Sweet smelling compounds are(Q-39)
(a) alcohol(b) Ether(c) Ester(d) Aldehyde
ChemistryChapter-21 (Subjective)Class Test-2
i.Which elements are commonly present in organic compound?
(Q-2)Carbon and hydrogen are always present; oxygen, nitrogen, sulfur, phosphorus and halogens are also commonly present.
ii.What is open chain? Give example.
(Q-5)Compounds whose carbon atoms are joined in straight or branched chains with free ends (no ring) are open chain (acyclic) compounds. Example: propane CH3CH2CH3.
iii.What is aromatic compounds?
(Q-9)Cyclic compounds that contain one or more benzene rings (alternate single and double bonds, usually with a pleasant smell) are aromatic compounds. Example: benzene C6H6, toluene.
iv.What is benzene? Write it’s characteristics.
(Q-10)Benzene (C6H6) is the simplest aromatic hydrocarbon, a six-carbon ring with alternate single and double bonds.
Characteristics: colourless liquid with a characteristic smell; insoluble in water but soluble in organic solvents; burns with a sooty flame; flat, stable ring.
v.Write any two characteristics of structural formula
(Q-12)1) It shows how the atoms are arranged and bonded in a molecule.
2) It can be used to distinguish isomers (same molecular formula, different structure).
2) It can be used to distinguish isomers (same molecular formula, different structure).
vi.Define condense formula. Give example.
(Q-14)A shortened structural formula in which bonds are omitted (or only some shown) and atoms are grouped with the carbon they are attached to. Example: ethane CH3CH3, ethyne CH≡CH.
vii.Define homologous series.
(Q-16)A series of organic compounds with the same functional group and general formula, in which each member differs from the next by a CH2 unit. Example: CH4, C2H6, C3H8.
viii.How do physical properties change in homologous series?
(Q-19)They change gradually: melting point, boiling point and density increase, and solubility in water decreases as the molecular mass increases.
ix.Why do methane, ethane and propane do not show isomerism?
(Q-21)Because with only 1, 2 or 3 carbon atoms there is only one possible way to arrange the atoms; branching needs at least four carbons.
x.Why structural isomerism occurs?
(Q-24)Because carbon atoms can join in different ways (straight or branched chains) giving different structures for the same molecular formula, e.g. butane and 2-methylpropane (C4H10).
xi.What is carboxylic group? Give example.
(Q-29)The functional group –COOH (carboxyl) of carboxylic acids. Example: ethanoic acid CH3COOH.
xii.What is root? Give an example.
(Q-31)The part of an IUPAC name that shows the number of carbon atoms in the longest chain (meth-, eth-, prop-, but-…). Example: in propanol the root is “prop” (3 carbons).
xiii.What is carbocyclic acids? Give it’s general formula.
(Q-36)Organic acids containing the carboxyl group (–COOH), also called carboxylic acids. General formula: RCOOH or CnH2n+1COOH.
xiv.How ester can prepare?
(Q-38)By heating a carboxylic acid with an alcohol in the presence of conc. H2SO4 (esterification):
RCOOH + R′OH → RCOOR′ + H2O
e.g. CH3COOH + C2H5OH → CH3COOC2H5 + H2O
RCOOH + R′OH → RCOOR′ + H2O
e.g. CH3COOH + C2H5OH → CH3COOC2H5 + H2O
