PYQ Vault

Day 101: 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: 2026 (same type asked 2 times)

    20
    The formula of functional group for aldehyde is :

    Tap an option to check your answer.

  2. Question 2

    Carbon and its Compounds. Asked once: 2026 (same type asked 2 times)

    29 (B)
    (i) How would you name the following : I. CH3−CH2−CHO\mathrm{CH_3{-}CH_2{-}CHO} II. CH3−C≡CH\mathrm{CH_3{-}C{\equiv}CH} (ii) When ethanol reacts with ethanoic acid in the presence of conc. H2SO4\mathrm{H_2SO_4}, a substance with sweet smell is produced. Answer the following : I. State the class of compounds to which the sweet smelling compounds belong. II. Write the chemical equation for the reaction. (iii) Why soaps do not produce foam with hard water ?

  3. Question 3

    Chemical Reactions and Equations. Asked once: 2026 (same type asked 2 times)

    26
    What happens when : (a) An iron nail is dipped in copper (II) sulphate solution ? (b) Potassium iodide solution is mixed with lead nitrate solution ? (c) Silver chloride is exposed to sunlight ? Write balanced chemical equations to support your answer.

  4. Question 4

    Chemical Reactions and Equations. Asked once: 2024 (same type asked 2 times)

    21 (b)
    What is meant by a balanced chemical equation ? Why is it necessary for the equation to be balanced ?

  5. Question 5 (case study, 4 parts)

    Control and Coordination. Asked once: 2025 (same type asked 2 times)

    The growth movements of plant parts in which the direction of the stimulus determines the direction of the response is known as tropic movements or tropism. Plants also have non-directional movements which may not be growth dependent.
    38 (I)
    Name the movement which causes ‘X’ and ‘Y’ to grow downwards and upwards respectively. (Refer above figure)
    38 (II)
    Write the name of a hormone that plays a major role in (i) falling of leaves (ii) rapid cell division
    38 (III) (a)
    Leaves of the sensitive plant move very quickly in response to ‘touch’. How is this stimulus of touch communicated and explain how the movement takes place.
    38 (III) (b)
    Name the plant hormone which is synthesized at the shoot tip. How does this hormone helps the plant to bend towards light ?