PYQ Vault

Day 221: CBSE Class 10 Science

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

  1. Question 1

    Our Environment. Asked once: 2023 (same type asked 4 times)

    33
    If a harmful chemical enters in a food chain comprising peacock, plants, rats and snakes, which of these organisms is likely to have the highest concentration of the chemical in its body. Justify your answer. Name the process involved and define it.

  2. Question 2

    Our Environment. Asked once: 2023 (same type asked 4 times)

    25
    Why is damage to the ozone layer a cause for concern ? What steps are being taken to limit this damage ?

  3. Question 3

    Our Environment. Asked once: 2023 (same type asked 4 times)

    26
    “Ozone, although a deadly poison, performs an essential function for the earth and its inhabitants.” Explain.

  4. Question 4

    Acids, Bases and Salts. Asked once: 2026

    22
    In which case/cases will the bulb glow considering that all other connections of electric circuit are complete and working ?

    Tap an option to check your answer.

  5. Question 5

    Carbon and its Compounds. Asked once: 2026

    29 (b)
    (i) Write the structural formula of benzene. (ii) State the reason why carbon can neither form C4+\mathrm{C^{4+}} cation nor C4−\mathrm{C^{4-}} anion. (iii) What type of bond is formed between carbon and hydrogen ? (iv) How is ethanol converted to ethanoic acid ? (v) Complete the following chemical equation : CH3COOC2H5+NaOH⟶\mathrm{CH_3COOC_2H_5 + NaOH \longrightarrow}