PYQ Vault

Day 109: CBSE Class 10 Science

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

  1. Question 1

    Carbon and its Compounds. Asked once: 2023 (same type asked 2 times)

    34 (b)
    (i) Name the compound formed when ethanol is heated at 443 K in the presence of conc.H2SO4\mathrm{H_2SO_4} and draw its electron dot structure. State the role of conc.H2SO4\mathrm{H_2SO_4} in this reaction. (ii) What is hydrogenation ? Explain it with the help of a chemical equation. State the role of this reaction in industry.

  2. Question 2

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

    21
    Name the type of chemical reaction in which calcium oxide reacts with water. Justify your answer by giving balanced chemical equation for the chemical reaction.

  3. Question 3

    Electricity. Asked once: 2022 (same type asked 2 times)

    13
    An electric motor rated 1100 W is connected to 220 V mains. Find : (i) The current drawn from the mains, (ii) Electric energy consumed if the motor is used for 5 hours daily for 6 days. (iii) Total cost of energy consumed if the rate of one unit is ₹ 5.

  4. Question 4

    Electricity. Asked once: 2024 (same type asked 2 times)

    36 (a)
    (i) Which type of circuits — series or parallel, should be used when you have to operate different electrical gadgets in your house ? List two reasons for your answer. (ii) Find the current flowing through the following electric circuit :

  5. Question 5

    Carbon and its Compounds. Asked once: 2024 (same type asked 5 times)

    34 (a)
    (i) Give reason why carbon can neither form C4+\mathrm{C^{4+}} cations nor C4−\mathrm{C^{4-}} anions but form covalent compounds. (ii) What is homologous series of carbon compound ? Write the molecular formula of any two consecutive members of homologous series of aldehydes. (iii) Draw the structure of the molecule of cyclohexane (C6H12)(\mathrm{C_6H_{12}}).