Chemistry Class 10 FBISE Paper Pattern and Most Repeated Questions

Built from the 13 book chapters (Units 1 to 13) and the FBISE 2025 and 2026 papers (2026 Sets B, D and M were read in full). Each chapter has: key definitions, equations and formulas, must-know points, and the past-paper questions with short model answers and worked numericals. Numericals use the atomic masses printed on the paper (H 1, C 12, N 14, O 16, Na 23, Mg 24, Al 27, S 32, Cl 35.5, K 39, Ca 40). Fe, Cu and Zn are not in that table, so the paper gives them in the question (Zn = Cu = 63.5).

Paper pattern

• Section A: 12 MCQs (20 minutes). Section B: 11 short parts of 3 marks each (33 marks), every part has an OR choice, marks split like 1+2, 2+1, 1.5+1.5 or 1x3. Section C: 4 long questions (20 marks), each with an OR, split like 2+2, 3+3, 1.5x4.
• Important: the 2026 papers (Sets B, D, M) follow the new NBF book (electrolysis, fuel cells, polymers, vitamins, amino acids, empirical formula). The 2025 paper still used the old syllabus (hardness of water, Solvay process, urea, Kc, Lewis acids, ozone). Those old topics are NOT in your NBF book, so they are left out here. Study the book chapters below.
• Every numerical on the 2026 papers is one of four types: empirical and molecular formula, molarity in mol/dm³ or g/dm³, limiting reactant with mass of product, or reacting mass of a gas.

Most repeated questions (appear in all of Sets B, D and M)

• Empirical formula from percentage composition, then molecular formula from molar mass (CH₂O with M = 60, 90 or 180 appears again and again).
• Molarity in mol/dm³ (or g/dm³) of a solution: 20 g NaOH, 10 g NaCl, 10 g Na₂CO₃, 9.8 g H₂SO₄ in 0.5 dm³, 0.25 mol KNO₃.
• Limiting reactant and mass of product (Zn with H₂SO₄, CaCO₃ with HCl, Na₂CO₃ with HCl).
• Classify SO₂, CO₂, CuO, CaO and Al₂O₃ as acidic, basic or amphoteric, with equations.
• Hydrogen-oxygen fuel cell: advantages over petrol engines, and the reactions at anode and cathode.
• Standard electrode potentials: which metal is more reactive (Zn or Al against Cu). Daniell cell diagram. Electroplating uses and chrome plating.
• Structural and displayed formula of propan-1-ol, butan-1-ol, butan-2-ol. Preparation of ethene (dehydration of an alcohol, dehydrohalogenation, or steam with ethene giving ethanol).
• Esterification (general word equation and an example). Complete combustion of methanol or ethanol.
• Fractional distillation: what it means, two fractions, uses, and how properties change bottom to top.
• Haber process (equation with conditions) and Contact process (catalyst, conditions).
• Vitamins A, C and D: two sources and one function (or deficiency disease). Amino acid general structure, dipeptide, protein.
• Polymers: monomer and polymer, addition against condensation, polyamide from a dicarboxylic acid and a diamine. Plastics: landfill and ocean problems.
• Why ionic compounds have high melting points. Metals with steam, oxygen, cold water and dilute acid. Role of kinetics in the food industry. Rate graph questions.

2026 Section A (MCQ) answers, Set B, for revision

• Reduction half-equation: Ag⁺ + e⁻ → Ag. Sublimation: solid to gas. Anode of an electrolytic cell: positively charged. Exothermic reaction rate increases with temperature. Soluble salt: sodium chloride. Soluble salt from acid and alkali: titration. Catalyst in Contact process: V₂O₅. Steeper slope: faster reaction. Excess metal removed by filtration. 1 dm³ = 1000 cm³. C₂H₅OH + 2[O] with KMnO₄/H₂SO₄ gives CH₃COOH. Ethanol is blended with petrol.