PYQ Vault

Day 4: CBSE Class 10 Science

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

  1. Question 1

    Our Environment. Asked 4 times: 2022*, 2023*, 2024*, 2025 (* = numbers or wording changed that year)

    33
    Some harmful chemicals get accumulated in human bodies through the food chain. Name this phenomenon. Explain the reason of maximum concentration of these chemicals found in our bodies.

  2. Question 2

    Acids, Bases and Salts. Asked 3 times: 2023*, 2024*, 2026 (* = numbers or wording changed that year)

    18
    To a small amount of copper oxide in a beaker, when we add dilute hydrochloric acid slowly with stirring, the change in the colour of the solution is due to the formation of :

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  3. Question 3

    Acids, Bases and Salts. Asked 3 times: 2023*, 2024*, 2026 (* = numbers or wording changed that year)

    22
    Four solutions, namely fructose, ethanol, hydrochloric acid and sodium hydroxide filled in four separate beakers are connected one by one in an electric circuit with a bulb. The solutions in which the bulb will glow when current is passed are :

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  4. Question 4

    Acids, Bases and Salts. Asked 3 times: 2024*, 2025*, 2026 (* = numbers or wording changed that year)

    17
    Tamarind is a natural source of which acid ?

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  5. Question 5

    Acids, Bases and Salts. Asked 3 times: 2023*, 2024*, 2026 (* = numbers or wording changed that year)

    27 (A)
    (a) Give the chemical name and formula of Plaster of Paris. (b) Write the chemical equation of its preparation. (c) Give any two uses of it.