PYQ Vault

Day 84: CBSE Class 10 Science

5 questions. Try each one first, then open its answer.

  1. Question 1

    Acids, Bases and Salts. Asked once: 2025 (same type asked 3 times)

    22
    (a) Write the formula of the ions which (i) acids, and (ii) bases generate in water solutions. (b) Dry HCl\mathrm{HCl} gas does not change the colour of dry litmus paper. Why ?

  2. Question 2

    Acids, Bases and Salts. Asked once: 2024 (same type asked 3 times)

    27
    Write the common name and the chemical name of the compound CaSO4⋅12 H2O\mathrm{CaSO_4 \cdot \frac{1}{2}\,H_2O}. Write the method of its preparation. Give chemical equation for the reaction, when water reacts with CaSO4⋅12 H2O\mathrm{CaSO_4 \cdot \frac{1}{2}\,H_2O}.

  3. Question 3

    Acids, Bases and Salts. Asked once: 2025 (same type asked 3 times)

    28 (a)
    State the chemical property in each case on which the following uses of baking soda are based upon : (i) as an anti-acids (ii) as a constituent in making baking powder (iii) in soda-acid fire-extinguishers

  4. Question 4

    Acids, Bases and Salts. Asked once: 2025 (same type asked 3 times)

    4
    Consider the following reactions : (i) Dilute hydrochloric acid reacts with sodium hydroxide. (ii) Magnesium oxide reacts with dilute hydrochloric acid. (iii) Carbon dioxide reacts with sodium hydroxide. It is found that in each case :

    Tap an option to check your answer.

  5. Question 5

    Acids, Bases and Salts. Asked once: 2026 (same type asked 3 times)

    25
    Why does one feels pain and irritation when stung by honey-bee ? Rubbing of baking soda on the stung area gives relief. How ?