PYQ Vault

Day 67: CBSE Class 10 Science

5 questions (8 parts). Try each one first, then open its answer.

  1. Question 1

    Metals and Non-metals. This type asked 2 times: 2025, 2026. This one: 2026

    25
    Show the formation of NaCl\mathrm{NaCl} by transfer of electrons. Why does solid NaCl\mathrm{NaCl} not conduct electricity ? [Atomic number : Na = 11, Cl = 17]

  2. Question 2 (case study, 4 parts)

    Metals and Non-metals. This type asked 2 times: 2024, 2026. This one: 2026

    An electrochemical process is used for refining metals by selectively dissolving and depositing them through electrolysis. Electrolytic refining is used for metals like Copper, Zinc, Tin, Nickel, Silver and Gold.
    28 (a)
    Define anode mud.
    28 (b)
    In electrolytic refining of copper, name the anode and the cathode.
    28 (c) (i)
    With the help of chemical equations, show the extraction of copper from its ore Cu2S\mathrm{Cu_2S}.
    28 (c) (ii)
    Draw a neat and labelled diagram showing electrolytic refining of copper.

  3. Question 3

    Metals and Non-metals. This type asked 2 times: 2025, 2026. This one: 2026

    22
    Alloys are homogeneous mixture of metal with a metal or non-metal. Which among the following alloys contain non-metal as one of its constituents ?

    Tap an option to check your answer.

  4. Question 4

    Our Environment. This type asked 2 times: 2022, 2026. This one: 2026

    7
    In an ecosystem, the decomposers perform an important role. Select the option indicating the role of decomposers.

    Tap an option to check your answer.

  5. Question 5

    Acids, Bases and Salts. This type asked 2 times: 2024, 2025. This one: 2025

    27
    Write chemical formula of washing soda. How is it obtained from baking soda ? List two uses of washing soda.