As per your request, the questions from previous years (chapter/topic-wise) collected from attached sources, along with the years they were asked in, are given below.
Chemistry
Chemical Reactions and Equations
- Write one difference between displacement and double displacement reactions. (2013)
- Write the balanced equation for the combustion of methane. (2013)
- Identify X, Y, and Z in the following equations — i) Cu + CO₂ → Green substance (X); ii) Ag + Y → Black substance (Ag₂S); iii) FeSO₄ → Fe₂O₃ + SO₃ + Z (2013)
- What happens when— i) CuSO₄(aq) + Fe(s) → ?; ii) Zn(s) + H₂SO₄(l) → ?; iii) Na(s) + O₂(g) → ? (2013)
- Write one difference between oxidation and reduction. (2013 Supp.)
- Balance the following equation— Pb(NO₃)₂ → PbO + NO₂ + O₂. (2013 Supp.)
- Give one example of a redox reaction. (2014)
- Write one example each of a combination reaction and a decomposition reaction. (2015)
- In the reaction CuO + H₂ → Cu + H₂O, which substance is oxidized and which is reduced? Give one more example of this type of reaction. (2015)
- What is a combination reaction? Write the combination reaction between quicklime and water. (2016)
- Explain with examples: (a) Displacement reaction (b) Neutralization reaction (c) Redox reaction. (2018 Supp.)
- Write one difference in any of the following: (a) Positive and negative catalyst (b) Thermal decomposition and electrolytic decomposition (c) Combination and displacement reaction. (2018)
- In the reaction CuO + H₂ → Cu + H₂O, name the reactant that gets reduced. (2023)
- Explain each of the following with one example: i) Combination reaction ii) Decomposition reaction. (2023)
- In the balanced equation of the reaction Fe + H₂O → Fe₃O₄ + H₂, what will be the coefficient of Fe? (2024)
- Na₂CO₃(s) + 2HCl(aq) → [X] + H₂O(l) + CO₂(g) — Write the chemical name and formula of compound [X]. (2024)
- Copper (II) oxide + Hydrogen → Copper + Water. Write the balanced chemical equation for the above word equation. (2024)
- Iron + Copper sulphate → Iron sulphate + Copper. Write the balanced chemical equation for the above word equation. (2024)
- Zinc + Copper sulphate → Zinc sulphate + Copper. Write the balanced chemical equation for the above word equation. (2024 Supp.)
- Sodium sulphate + Barium chloride → Barium sulphate + Sodium chloride. Write the balanced chemical equation for the above word equation. (2024 Supp.)
Acids, Bases and Salts
- Match column A with column B: (i) Strong acid, (ii) Weak acid, (iii) Per-acid, (iv) Strong base, (v) Weak base, (vi) Neutral salt, (vii) Acidic salt, (viii) Basic salt, (ix) Natural indicator, (x) Synthetic indicator. (2013)
- Write the names of any two synthetic indicators. (2015)
- Which will have higher pH: (i) Blood or distilled water? (ii) Gastric juice or lemon juice? (2015)
- When zinc reacts with sulphuric acid, gas X is evolved— (i) Name gas X. (ii) Write the equation of the reaction. (iii) How will you identify gas X? (2015)
- Among the following, which is a strong acid and which is a strong base— (a) Acetic acid or Hydrochloric acid (b) Sodium hydroxide or Calcium hydroxide. (2016)
- Write the chemical formulae of bleaching powder and plaster of Paris and mention one use of each. (2017 Sp. Supp.)
- (a) Write two properties of acids. (b) Define strong acid and weak acid. (c) What is water of crystallization? (2017 Sp. Supp.)
- What is the effect of the concentration of hydrogen ions [H⁺] on the nature of a solution? (2017)
- When diluting an acid, why is acid added to water and not water to acid? Give reason. (2017)
- Write the names of acids present in orange and tamarind. (2017)
- What is meant by the chlor-alkali process? (2017)
- What happens when— i) Phenolphthalein is added to an alkaline solution? ii) Methyl orange is added to an acidic solution? iii) A white cloth stained with vegetables is washed with soap? iv) Fried food items are left open in the air? (2013 Supp.)
- What is the pH value of a neutral solution? (2014)
- Name the acid secreted by an ant’s sting. (2014)
- Write the two main components of baking powder. (2016)
- Draw a labeled diagram showing the conduction of electricity through an aqueous solution of acid. (2022)
- Write the difference between acids and bases on the basis of taste. (2022)
- Write the cause of tooth decay. (2022)
- Write the chemical name and formula of bleaching powder. (2020)
- Write Arrhenius’ concept of acids and bases. (2020)
- When electricity is passed through an aqueous solution of common salt, gases X and Y are liberated. Gas X burns with a pop sound, and gas Y is used to disinfect water. Name gases X and Y. (2022)
- Write one example of an olfactory indicator. (2023)
- The chemical name of the acid present in vinegar is ……………. (2023)
- Define neutralization reaction. (2023)
- Write the chemical formula of plaster of Paris. (2021)
- Write the number of molecules of water of crystallization present in one molecule of alum. Also define neutralization. (2021)
- Write the conjugate acid of NH₃. (2021)
- Write the conjugate base of H₂O. (2021)
- Write the conjugate base of HCl. (2021)
- Why are metallic oxides basic in nature? Explain. (2024 Supp.)