Acids, Bases and Salts
12 solved questions from Class 10 Science, each with the full working. Tap any question to see the step-by-step solution.
- 1 Calculate the pH of a 0.01 M solution of hydrochloric acid (HCl). Give your answer correct to two decimal places. medium 3 marks pH of strong acid solution
- 2 Which of the following correctly defines the pH of a solution? easy MCQ 1 mark Definition of pH
- 3 Calculate the pH of a 0.10 M solution of sodium hydroxide (NaOH). Give your answer correct to two decimal places. easy 2 marks pH of strong bases
- 4 Which of the following indicators turns from yellow to red when added to an acidic solution? easy MCQ 1 mark Indicators
- 5 A 25.0 mL sample of 0.10 M acetic acid (CH_3COOH) is titrated with 0.10 M NaOH. Calculate the pH of the solution at the half‑equivalence point. (Acetic acid K_a = 1.8×10^-5.) Give your answer correct to two decimal places. hard 5 marks Half‑equivalence point in weak acid–base titration
- 6 Rahul added dilute hydrochloric acid to solid sodium hydrogen carbonate taken in a test tube. A gas was evolved which turned lime water milky. When the gas was passed through lime water in excess, the milkiness disappeared. Explain the chemical reactions involved by writing balanced chemical equations for both stages. medium 3 marks Reaction of carbonates with acids and lime water test
- 7 Plaster of Paris (CaSO_4 · 1/2H_2O) sets into a hard solid mass on mixing with water. Write the balanced chemical equation for this setting reaction. Also, calculate the percentage of water of crystallisation by mass present in hydrated copper sulphate (CuSO_4 · 5H_2O). (Given atomic masses: Cu = 63.5 u, S = 32 u, O = 16 u, H = 1 u) medium 3 marks Plaster of Paris and water of crystallisation calculation
- 8 During the chlor-alkali process for the industrial preparation of sodium hydroxide, electricity is passed through an aqueous solution of sodium chloride (brine). Which gases are liberated at the anode and cathode respectively? easy MCQ 1 mark Products of chlor-alkali process
- 9 A student tests three oxides X, Y, and Z with litmus paper and records the following observations: (i) Oxide X dissolves in water to turn blue litmus red. (ii) Oxide Y dissolves in water to turn red litmus blue. (iii) Oxide Z reacts with both dilute hydrochloric acid and sodium hydroxide solution to form salt and water. Identify the general nature (acidic, basic, or amphoteric) of oxides X, Y, and Z. Give one example of a chemical formula for each type of oxide. hard 5 marks Nature of metallic, non-metallic, and amphoteric oxides
- 10 An aqueous solution of hydrochloric acid has a pH of 2. If this solution is diluted by adding a large amount of distilled water, will the pH value increase, decrease, or remain the same? What maximum limit will the pH approach upon extreme dilution at 25°C? Explain why concentrated acid should always be added to water slowly with constant stirring, rather than water to acid. hard 3 marks Dilution of acids and pH scale limits
- 11 What is the primary topic or theoretical principle explored in 'Acids, Bases and Salts' (Class 10 SCIENCE)? medium MCQ Chapter Core Principle
- 12 Which key mechanism or analytical rule is highlighted in 'Acids, Bases and Salts'? medium MCQ Key Analytical Mechanism