शि

Home · Schooling · CBSE · Class 10 · Science · Acids, Bases and Salts · In-text questions (page 33)

NCERT Class 10 Science Acids, Bases and Salts: In-text questions (page 33) Solutions

AI-written, checked on 23 Oct 2026

Solutions written by Shishya, checked — not the board's official answers

Step-by-step working for every question of In-text questions (page 33) in NCERT's Class 10 Science book, chapter “Acids, Bases and Salts”, written by Shishya. Each question is in our own short words; open the NCERT chapter for the exact wording and figures.

NCERT chapter (PDF) ↗हिंदी में पढ़ें

How these were checked: the solutions were drafted with AI and then read and corrected on 23 Oct 2026. Every numerical final answer is recomputed from the question's own numbers by a calculator check that runs before each release; proofs and explanations were read, not machine-checked. The NCERT textbook is the authority — if something here disagrees with it, follow the book.

Tap “why?” under a step to see the textbook rule it uses — from Shishya's fixed list of NCERT Class 9-10 rules, not written by AI for this page. A step without one has no rule from the list yet.

Stuck on a step?

Ask the AI tutor about this chapter — it gives hints before answers — or snap a photo of your own question to get worked steps. You will be talking to an AI, not a person. For ages 13 and up; the first answer of each is free.

Ask the AI tutor about this chapter →📷 Snap a question →

  1. In-text (page 33) Q1

    What is the common name of Ca(OCl)₂?

    1. The chemical formula Ca(OCl)₂ represents a compound formed by the reaction of chlorine with calcium hydroxide.
    2. This compound is widely used as a bleaching agent in the textile and paper industries.
    3. Its common name is bleaching powder.

    Answer: Bleaching powder

    Report an error in this solution

  2. In-text (page 33) Q2

    Name the substance that gives bleaching powder when treated with chlorine.

    1. Bleaching powder is chemically known as calcium oxychloride, with the formula Ca(OCl)Cl.
    2. It is prepared by passing chlorine gas over dry slaked lime.
    3. Slaked lime is the common name for calcium hydroxide, which has the formula Ca(OH)₂.
    4. The reaction between chlorine and calcium hydroxide produces bleaching powder and water.
    5. Therefore, the substance that reacts with chlorine to form bleaching powder is calcium hydroxide.

    Answer: Calcium hydroxide (slaked lime)

    Report an error in this solution

  3. In-text (page 33) Q3

    Name the sodium compound used for softening hard water.

    1. Hard water contains dissolved calcium and magnesium salts that form insoluble precipitates with soap.
    2. Sodium carbonate decahydrate, commonly known as washing soda, is used to remove these hardness-causing ions.
    3. It reacts with calcium and magnesium ions to form insoluble carbonates, which are then removed.
    4. This process softens the water, allowing soap to lather properly.

    Answer: Sodium carbonate decahydrate (washing soda)

    Report an error in this solution

  4. In-text (page 33) Q4

    What happens when a solution of sodium hydrogencarbonate is heated? Give the equation.

    1. Thermal decomposition occurs when sodium hydrogencarbonate is heated strongly.
    2. The compound breaks down into sodium carbonate, water, and carbon dioxide gas.
    3. The balanced chemical equation for this reaction is 2NaHCO3 → Na2CO3 + H2O + CO2.
      why?

      A balanced equation has the same number of atoms of each element on both sides, because atoms are neither created nor destroyed in a chemical reaction (law of conservation of mass). Only the numbers in front (coefficients) change, never the formulas.

    Answer: 2NaHCO3 → Na2CO3 + H2O + CO2

    Report an error in this solution

  5. In-text (page 33) Q5

    Write an equation for the reaction of Plaster of Paris with water.

    1. Plaster of Paris is calcium sulphate hemihydrate, written as CaSO₄ · ½H₂O.
    2. When water is added, it reacts to form gypsum, which is calcium sulphate dihydrate, CaSO₄ · 2H₂O.
    3. It takes up 1½ molecules of water per formula unit (½ + 1½ = 2): CaSO₄ · ½H₂O + 1½H₂O → CaSO₄ · 2H₂O, and the paste sets into a hard mass.

    Answer: CaSO₄ · ½H₂O + 1½H₂O → CaSO₄ · 2H₂O (Plaster of Paris + water → gypsum)

    Report an error in this solution

Other exercises in this chapter

← Acids, Bases and Salts: notes, practice and all exercises

Saved for offline

Saves these solutions in this browser on this phone. No sign-in; nothing about you is saved or sent. A saved copy is not updated until you save it again. Parts that load from the server when you use them (the AI tutor, adaptive practice, sign-in) still need a connection.