PYQ Vault

Day 104: CBSE Class 10 Science

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

  1. Question 1 (case study, 4 parts)

    Metals and Non-metals. Asked once: 2024 (same type asked 2 times)

    The metals produced by various reduction processes are not very pure. They contain impurities, which must be removed to obtain pure metals. The most widely used method for refining impure metals is electrolytic refining.
    37 (i)
    What is the cathode and anode made of in the refining of copper by this process ?
    37 (ii)
    Name the solution used in the above process and write its formula.
    37 (iii) (A)
    How copper gets refined when electric current is passed in the electrolytic cell ?
    37 (iii) (B)
    You have two beakers ‘A’ and ‘B’ containing copper sulphate solution. What would you observe after about 2 hours if you dip a strip of zinc in beaker ‘A’ and a strip of silver in beaker ‘B’? Give reason for your observations in each case.

  2. Question 2

    Metals and Non-metals. Asked once: 2025 (same type asked 2 times)

    Two statements are given, one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer from the options given below.
    17
    Assertion (A) : Brass is prepared by first melting copper and then dissolving tin into it in a definite proportion. Reason (R) : The primary metal of brass is copper.

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  3. Question 3

    Our Environment. Asked once: 2026 (same type asked 2 times)

    Two statements are given, one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer from the options given below.
    8
    Assertion (A) : Natural replenishment of soil will not take place in absence of microbes. Reason (R) : Microbes, comprising of bacteria and fungi, break down dead remains and waste products of organisms, and they go into the soil.

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  4. Question 4

    Acids, Bases and Salts. Asked once: 2024 (same type asked 2 times)

    34 (b)
    Common salt is a very important raw material as many compounds of industrial use can be prepared from it. Explain, giving chemical equations, the method of preparation of washing soda from sodium chloride. List four industrial/domestic uses of washing soda.

  5. Question 5

    Acids, Bases and Salts. Asked once: 2025 (same type asked 2 times)

    3
    A common feature observed in the crystals of washing soda, copper sulphate, gypsum and ferrous sulphate is that all

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