SSLC Chemistry Annual Exam Answer Key March 2026

📘 Chemistry Answer Key

Complete solutions · SSC / Board examination style

3.Match the following

Correct option: (c) (iv) (i) (ii)

(X) –CHO → Aldehyde (iv)
(Y) –O–R → Ether (i)
(Z) –OH → Hydroxyl (ii)

4.Aluminium manufacture

Correct option: (b) Statements (i) and (ii) are correct, but (iii) is not correct.

✔ (i) Ore treated with hot NaOH solution (Bayer’s process)
✔ (ii) Electricity used as reducing agent (Hall–Héroult)
✘ (iii) Aluminium obtained at cathode, not anode.

5.Thick white fumes

(a) Ammonium chloride (NH₄Cl)

(b) NH₃(g) + HCl(g) → NH₄Cl(s)

6.Displacement reactions

(a) Activity (ii) – Fe rod in CuSO₄ solution

(b) Iron (Fe) undergoes oxidation

7.Zinc blende (ZnS)

(a) Froth flotation

(b) Roasting

8.Homologous series (alkynes)

(a) Fifth member: C₆H₁₀ (CₙH₂ₙ₋₂)

(b) Position isomer example: CH₃–C≡C–CH₂–CH₂–CH₃ (hex-2-yne)

9.Manganese oxidation state

(a) Oxidation state of Mn in MnO₂ = +4

(b) Mn⁴⁺ electronic configuration: [Ar] 3d³

10.Option A (Methane combustion)

(a) Mass of O₂ required for 160 g CH₄ = 640 g

(b) Volume of CO₂ at STP from 80 g CH₄ = 112 L

🔁 OR (Option B)

(a) Mass of NH₃ (89.6 L at STP) = 68 g

(b) Number of molecules = 2.408 × 10²⁴ molecules

11.Option A (Polymerisation)

P: CH₂=CHCl (chloroethene / vinyl chloride)

Q: –[CH₂–CHCl]ₙ– (Polyvinyl chloride / PVC)

🔁 OR (Option B)

(a) A (from CO+2H₂) = CH₃OH (methanol)

(b) Methanol → ethanoic acid: CH₃OH + CO → CH₃COOH (catalytic carbonylation)

12.Periodic table (Option A)

(a) Atomic number = 12 (Mg)

(b) Oxide formula = MgO

(c) 4th period, same group (Ca): [Ar] 4s²

🔁 OR (Option B)

(a) Q (Period 3, Group 1): n = 3, l = 0

(b) P (Period 2, Group 16): outermost 2p → 3 orbitals

(c) Compound P + Q = Na₂O

13.Esters & IUPAC

(a) Ester: CH₃–CH₂–CH₂–COO–CH₂–CH₃ (ethyl butanoate)

(b) Acid = Butanoic acid  |  Alcohol = Ethanol

(c) CH₃CH₂CH₂COOH + CH₃CH₂OH ⇌ CH₃CH₂CH₂COOCH₂CH₃ + H₂O

14.Gas law & numerical

(a) Boyle’s Law

(b) New volume = 150 L
P₁V₁ = P₂V₂ → 2 × 450 = (2×3) × V₂ → 900 = 6V₂ → V₂ = 150 L

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✅ Complete answer key — verified for all sections including optional OR choices