Class 10 SEBA Science Chapter 2 Solutions – Acids, Bases and Salts (2026–27) | Assam Eduverse
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SEBA Class 10 Science Chapter 2 Acids, Bases and Salts solutions are prepared by Assam Eduverse strictly according to the latest SEBA / ASSEB syllabus 2026–27. These SEBA Class 10 Science Chapter 2 Acids, Bases and Salts solutions are created for students searching specifically for SEBA Class 10 Science Chapter 2 Acids, Bases and Salts solutions that are accurate, updated, and exam-oriented. This page provides complete SEBA Class 10 Science Chapter 2 Acids, Bases and Salts solutions, making it a trusted source for SEBA Class 10 Science Chapter 2 Acids, Bases and Salts solutions based on the official SEBA Class 10 Science textbook.
The SEBA Class 10 Science Chapter 2 Acids, Bases and Salts solutions explain all concepts included in SEBA Class 10 Science Chapter 2 Acids, Bases and Salts solutions, such as acids, bases, salts, chemical properties of acids and bases, pH scale, indicators, importance of pH in everyday life, common salts like washing soda and baking soda, and their uses. These SEBA Class 10 Science Chapter 2 Acids, Bases and Salts solutions help students understand theory, reactions, and definitions using SEBA Class 10 Science Chapter 2 Acids, Bases and Salts solutions written in simple and exam-friendly language, following the ASSEB Class 10 Science Chapter 2 solutions format.
With the complete SEBA Class 10 Science Chapter 2 Acids, Bases and Salts solutions (2026–27), students can prepare SEBA Class 10 Science Chapter 2 Acids, Bases and Salts solutions for intext questions and SEBA Class 10 Science Chapter 2 Acids, Bases and Salts solutions for chapter-end textbook exercise questions. These SEBA Class 10 Science Chapter 2 Acids, Bases and Salts solutions include important question answers, chemical equations, and exam-focused explanations. Assam Eduverse ensures every SEBA Class 10 Science Chapter 2 Acids, Bases and Salts solution is syllabus-based and exam-focused.
SEBA / ASSEB Class 10 Science Chapter 2 – Acids, Bases and Salts Intext Questions & Answers (Latest Syllabus 2026–27)
Page 18
Page 18Q1: You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?
Answer: Dip the red litmus paper into each test tube:
- The solution that turns red litmus blue is the basic solution.
- Use the blue litmus paper formed to test the remaining solutions. The one that turns blue litmus red is the acidic solution.
- The solution that does not change the color of either red or blue litmus paper is distilled water.
Page 22
Q1: Why should curd and sour substances not be kept in brass and copper vessels?
Answer: Curd and sour substances contain acids which can react with the metal of brass and copper vessels, forming poisonous compounds that can cause food poisoning.
Q2. Which gas is usually liberated when an acid reacts with a metal? Illustrate with an example. How will you test for the presence of this gas?
Answer:
When an acid reacts with a metal, hydrogen gas (H₂) is usually liberated.
Example:
When zinc (Zn) reacts with dilute hydrochloric acid (HCl), zinc chloride (ZnCl₂) and hydrogen gas (H₂) are formed:
Chemical Equation:Zn + 2HCl → ZnCl₂ + H₂
Test for Hydrogen Gas:
Bring a burning matchstick or splint near the mouth of the test tube where the gas is being released. If it burns with a ‘pop’ sound, it confirms the presence of hydrogen gas.
Q3. Metal compound A reacts with dilute hydrochloric acid to produce effervescence. The gas evolved extinguishes a burning candle. Write a balanced chemical equation for the reaction if one of the compounds formed is calcium chloride.
Answer:
The gas evolved that extinguishes a burning candle is carbon dioxide (CO₂). This means metal compound A is likely calcium carbonate (CaCO₃).
When calcium carbonate (CaCO₃) reacts with dilute hydrochloric acid (HCl), it forms calcium chloride (CaCl₂), carbon dioxide (CO₂), and water (H₂O).
Balanced Chemical Equation:CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O
Explanation:
Effervescence occurs due to the release of CO₂ gas.
The CO₂ gas extinguishes a flame as it does
Page 25
Q1: Why do HCl, HNO3, etc., show acidic characters in aqueous solutions while solutions of compounds like alcohol and glucose do not show acidic character?
Answer: HCl and HNO3 ionize in aqueous solutions to produce H+ ions, which are responsible for acidic properties. Alcohol and glucose do not ionize to produce H+ ions in aqueous solutions, hence they do not exhibit acidic properties.
Q2: Why does an aqueous solution of an acid conduct electricity?
Answer: In aqueous solutions, acids ionize to produce H+ ions. These ions are charged particles that can move freely in the solution, allowing it to conduct electricity.
Q3: Why does dry HCl gas not change the color of the dry litmus paper?
Answer: Dry HCl gas does not ionize to produce H+ ions in the absence of water. Since the acidic property is due to the presence of H+ ions, dry HCl gas does not exhibit acidic behavior and thus does not change the color of dry litmus paper.
Q4: While diluting an acid, why is it recommended that the acid should be added to water and not water to the acid?
Answer: Adding acid to water allows the heat generated to be absorbed by the larger volume of water, minimizing the risk of splashing and accidents. Adding water to concentrated acid can cause the mixture to splash due to the exothermic reaction, posing a safety hazard.
Q5: How is the concentration of hydronium ions (H3O+) affected when a solution of an acid is diluted?
Answer: Diluting an acid decreases the concentration of hydronium ions (H3O+) per unit volume, reducing the acidity of the solution.
Q6: How is the concentration of hydroxide ions (OH–) affected when the solution of a base is diluted?
Answer: Diluting a base decreases the concentration of hydroxide ions (OH–) per unit volume, reducing the basicity of the solution.
Page 28
Q1: You have two solutions, A and B. The pH of solution A is 6 and pH of solution B is 8. Which solution has more hydrogen ion concentration? Which of this is acidic and which one is basic?
Answer: Solution A, with pH 6, has a higher hydrogen ion concentration than solution B, with pH 8. Therefore, solution A is acidic, and solution B is basic.
Q2: What effect does the concentration of H+ (aq) ions have on the nature of the solution?
Answer: The concentration of H+ ions determines the acidity of the solution. Higher H+ ion concentration results in a more acidic solution, while lower H+ ion concentration results in a less acidic (or more basic) solution.
Q3: Do basic solutions also have H+ (aq) ions? If yes, then why are these basic?
Answer: Yes, basic solutions do have H+ ions, but they have a higher concentration of OH– ions compared to H+ ions. The excess of OH– ions imparts basicity to the solution.
Q4: Under what soil condition do you think a farmer would treat the soil of his fields with quick lime (calcium oxide) or slaked lime (calcium hydroxide) or chalk (calcium carbonate)?
Answer: If the soil is too acidic (low pH), a farmer would treat it with quick lime, slaked lime, or chalk to neutralize the excess acidity and bring the pH to a suitable level
Page 33
Q1: What is the common name of the compound CaOCl2?
Answer: The common name of CaOCl2 is bleaching powder.
Q2: Name the substance which on treatment with chlorine yields bleaching powder.
Answer: Dry slaked lime [Ca(OH)2] reacts with chlorine to produce bleaching powder.
Q3: Name the sodium compound which is used for softening hard water.
Answer: Washing soda (sodium carbonate, Na2CO3) is used for softening hard water.
Q4: What will happen if a solution of sodium hydrocarbonate is heated? Give the equation of the reaction involved.
Answer: Heating sodium hydrogen carbonate (NaHCO3) produces sodium carbonate (Na2CO3), carbon dioxide (CO2), and water (H2O).
2NaHCO3 → Na2CO3 + CO2 + H2O
Q5: Write an equation to show the reaction between plaster of Paris and water.
Answer: CaSO4·½H2O + 1½H2O → CaSO4·2H2O
Plaster of Paris reacts with water to form gypsum.
SEBA Class 10 Science Chapter 2 – Acids, Bases and Salts Textbook Exercise Questions & Solutions | 2026–27
Q1. A solution turns red litmus blue, its pH is likely to be
Answer: (d) 10
Explanation: A solution that turns red litmus blue is basic. A basic solution has a pH greater than 7. pH 10 is strongly basic among the options.
Q2. A solution reacts with crushed egg-shells to give a gas that turns lime-water milky. The solution contains
Answer: (b) HCl
Explanation: Eggshells contain calcium carbonate (CaCO₃), which reacts with hydrochloric acid (HCl) to release carbon dioxide (CO₂). CO₂ turns lime-water milky, confirming the presence of an acid.
Q3. 10 mL of a solution of NaOH is found to be completely neutralised by 8 mL of HCl. If we take 20 mL of the same NaOH solution, the amount of HCl required will be
Answer: (d) 16 mL
Explanation: The neutralisation reaction is directly proportional to the volume of the solutions. If 10 mL NaOH needs 8 mL HCl, then 20 mL NaOH will require 16 mL HCl.
Q4. Which one of the following types of medicines is used for treating indigestion?
Answer: (c) Antacid
Explanation: Antacids neutralise excess stomach acid, relieving indigestion.
Q5. Write word equations and balanced chemical equations for the following:
(a) Dilute sulphuric acid reacts with zinc granules
Word Equation: Zinc + Sulphuric acid → Zinc sulphate + Hydrogen
Balanced Equation: Zn + H₂SO₄ → ZnSO₄ + H₂
(b) Dilute hydrochloric acid reacts with magnesium ribbon
Word Equation: Magnesium + Hydrochloric acid → Magnesium chloride + Hydrogen
Balanced Equation: Mg + 2HCl → MgCl₂ + H₂↑
(c) Dilute sulphuric acid reacts with aluminium powder
Word Equation: Aluminium + Sulphuric acid → Aluminium sulphate + Hydrogen
Balanced Equation: 2Al + 3H₂SO₄ → Al₂(SO₄)₃ + 3H₂↑
(d) Dilute hydrochloric acid reacts with iron filings
Word Equation: Iron + Hydrochloric acid → Iron chloride + Hydrogen
Balanced Equation: Fe + 2HCl → FeCl₂ + H₂↑
Q6. Activity to prove that compounds like alcohols and glucose do not act like acids
Activity:
Take two beakers and label them A and B.
In A, pour dilute HCl; in B, pour glucose solution.
Dip clean nails in both and connect them to a battery, bulb, and wires (like a conductivity tester).
The bulb glows in beaker A (HCl) but not in B (glucose).
Conclusion:
Though glucose contains hydrogen, it doesn’t ionize in water to release H⁺ ions, hence doesn’t conduct electricity or show acidic behaviour.
Q7. Why does distilled water not conduct electricity, whereas rainwater does?
Answer: Distilled water is pure and lacks free ions. Rainwater contains dissolved CO₂ forming carbonic acid, which ionizes and conducts electricity.
Q8. Why do acids not show acidic behaviour in the absence of water?
Answer: Acids release hydrogen ions (H⁺) only in aqueous solutions. Without water, ionisation does not occur, so acidic properties are not exhibited.
Q9. pH values of five solutions A (4), B (1), C (11), D (7), E (9):
(a) Neutral – D (pH 7)
(b) Strongly alkaline – C (pH 11)
(c) Strongly acidic – B (pH 1)
(d) Weakly acidic – A (pH 4)
(e) Weakly alkaline – E (pH 9)
Hydrogen-ion concentration in increasing order (stronger acid = higher [H⁺]):
C (11) < E (9) < D (7) < A (4) < B (1)
Q10. In which test tube will fizzing occur more vigorously and why?
Answer: Fizzing occurs more in test tube A with HCl. HCl is a strong acid and ionises completely, producing more H⁺ ions than acetic acid (a weak acid). Thus, the reaction with magnesium is faster, releasing more hydrogen gas.
Q11. Fresh milk has a pH of 6. How will the pH change as it turns into curd?
Answer: As milk turns into curd, lactic acid forms, decreasing the pH below 6. Hence, the curd is more acidic than fresh milk.
Q12. (a) Why does the milkman make milk slightly alkaline?
To prevent spoilage. An alkaline environment delays fermentation.
(b) Why does this milk take longer to set as curd?**
Curd formation requires acidic conditions. Since the milk is alkaline, more time is needed to reach the required acidity.
Q13. Why should Plaster of Paris be stored in a moisture-proof container?
Answer: Plaster of Paris absorbs moisture and gets converted to gypsum (CaSO₄·2H₂O), losing its usefulness as it hardens.
Q14. What is a neutralisation reaction? Give two examples.
Answer: A reaction in which an acid reacts with a base to form salt and water.
Examples:
HCl + NaOH → NaCl + H₂O
H₂SO₄ + Ca(OH)₂ → CaSO₄ + 2H₂O
Q15. Two important uses:
Washing Soda (Na₂CO₃·10H₂O):
Used in laundry as a cleaning agent.
Softens hard water.
Baking Soda (NaHCO₃):
Used in baking to produce CO₂ for fluffy texture.
Acts as an antacid for indigestion.
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