PYQ Vault

Day 32: CBSE Class 10 Science

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

  1. Question 1

    Acids, Bases and Salts. Asked 2 times: 2023*, 2024 (* = numbers or wording changed that year)

    34 (b)
    Name and state in brief the process which is used to prepare sodium hydroxide from sodium chloride. In this process along with the main product two gases ‘X’ and ‘Y’ are also given off at the two electrodes. Name ‘X’ and ‘Y’ specifying the name of their respective electrode at which each gas is obtained. One of these gases when reacts with dry calcium hydroxide produces a compound ‘Z’ which is widely used in water treatment plants and textile industries. Name Z and write chemical equation for the reaction involved in its formation.

  2. Question 2

    Acids, Bases and Salts. Asked 2 times: 2023*, 2024 (* = numbers or wording changed that year)

    3
    A chemical compound used in glass, soap and paper industries is

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  3. Question 3

    Carbon and its Compounds. Asked 2 times: 2022*, 2024 (* = numbers or wording changed that year)

    5
    The number of single and double bonds present in a molecule of benzene (C6H6\mathrm{C_6H_6}) respectively, are :

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  4. Question 4

    Chemical Reactions and Equations. Asked 2 times: 2023*, 2024 (* = numbers or wording changed that year)

    34 (b)
    (i) Write balanced chemical equation for the following word equation. Lead nitrate + Potassium iodide →\rightarrow Lead iodide + Potassium nitrate Is this a double displacement reaction ? Justify your answer. Name the compound precipitated and write the ions present in it. (ii) Write the method of preparation of Ca(OH)2\mathrm{Ca(OH)_2}. What happens when CO2\mathrm{CO_2} is passed through it ? Write balanced chemical equation for the reaction involved.

  5. Question 5

    Chemical Reactions and Equations. Asked 2 times: 2023*, 2024 (* = numbers or wording changed that year)

    7
    MnO2+4HCl→MnCl2+2H2O+Cl2\mathrm{MnO_2 + 4HCl \rightarrow MnCl_2 + 2H_2O + Cl_2} The reaction given above is a redox reaction because in this case :

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