PYQ Vault

Day 156: CBSE Class 10 Science

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

  1. Question 1

    Carbon and its Compounds. Asked once: 2024 (same type asked 3 times)

    6
    Identify a group of the unsaturated hydrocarbons from the following :

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  2. Question 2

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

    36 (a)
    (i) Butane had both Carbon – Carbon bonds as well as Carbon – Hydrogen bonds. Draw its structural formula and state the number of (1) C – H bonds and (2) C – C bonds in it. (ii) You have two carbon compounds with the molecular formula C3H6O\mathrm{C_3H_6O}. Name two compounds with this formula and also draw their structural formula.

  3. Question 3

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

    34 (b)
    (i) With the help of diagram, show the formation of micelles, when soap is applied on oily dirt. (ii) Take two test tubes X and Y with 10 mL of hard water in each. In test tube ‘X’, add few drops of soap solution and in test tube ‘Y’ add a few drops of detergent solution. Shake both the test tubes for the same period. (1) In which test tube the formation of foam will be more ? Why ? (2) In which test tube is a curdy solid formed ? Why ?

  4. Question 4 (case study, 4 parts)

    Carbon and its Compounds. Asked once: 2024 (same type asked 3 times)

    More than three million carbon compounds have been discovered in the field of chemistry. The diversity of these compounds is due to the capacity of carbon atoms for bonding with one another as well as with other atoms. Most of the carbon compounds are poor conductors of electricity and have low melting and boiling points.
    37 (a)
    Write the molecular formula of first two members of homologous series having functional group −Br\mathrm{{-}Br}.
    37 (b)
    Given below are the formulae of some functional groups : (i) −CHO\mathrm{{-}CHO}, (ii) −CO−\mathrm{{-}CO{-}} Write the name of these functional groups.
    37 (c)
    What would be observed on adding a 5% alkaline potassium permanganate drop by drop to some warm ethanol taken in a test tube ? State the role of KMnO4\mathrm{KMnO_4} in the reaction and write the chemical equation for the reaction involved.
    37 (c) OR
    Write the name of the compound formed when ethanol is heated at 443 K temperature with excess of conc. H2SO4\mathrm{H_2SO_4}. What is the role of conc. H2SO4\mathrm{H_2SO_4} in the reaction ? Write the chemical equation for the reaction involved.

  5. Question 5

    Chemical Reactions and Equations. Asked once: 2025 (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.
    17
    Assertion (A) : Decomposition reactions are generally endothermic reactions. Reason (R) : Decomposition of organic matter into compost is an exothermic process.

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