PYQ Vault

Day 122: CBSE Class 10 Science

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

  1. Question 1

    Acids, Bases and Salts. Asked once: 2023 (same type asked 3 times)

    27
    (a) Write a balanced equation to show the reaction that occurs when a piece of aluminium is dipped in a dilute solution of (i) sulphuric acid and (ii) sodium hydroxide. (b) Write the colour of the solution formed when copper oxide is treated with hydrochloric acid. Give reason for this observation.

  2. Question 2

    Acids, Bases and Salts. Asked once: 2023 (same type asked 3 times)

    1
    When Sodium bicarbonate reacts with dilute hydrochloric acid, the gas evolved is :

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  3. Question 3

    Carbon and its Compounds. Asked once: 2026 (same type asked 3 times)

    Two statements are given, one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer from the options given below.
    24
    Assertion (A) : Carbon shares its valence electrons with other atoms of carbon or with atoms of other elements. Reason (R) : The shared electrons belong to the outermost shells of both the atoms and lead to both atoms attaining the noble gas configuration.

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  4. Question 4

    Carbon and its Compounds. Asked once: 2023 (same type asked 3 times)

    6
    When ethanol reacts with sodium two products are formed. These products are :

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  5. Question 5

    Carbon and its Compounds. Asked once: 2025 (same type asked 3 times)

    4
    Select from the following a hydrocarbon having one C−C\mathrm{C{-}C} bond and one C≡C\mathrm{C{\equiv}C} bond :

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