2. Questions Bank
  3. 8th Class
  4. Science
  5. Combustion and Flame

8th Class Science Combustion and Flame Question Bank Combustion and Flame HOTS Objective Problems

  • question_answer
    Radhika took some sodium bicarbonate in a conical flask and set up the apparatus as shown in the given diagram. She added cone. sulphuric acid into the conical flask using a funnel.
    Which of the flowing statements is correct for the given experiment?

    A)   The gas coming out of the delivery tube is heavier than air and will make the candle glow brightly.

    B)  The gas coming out of the delivery tube is lighter than air and will extinguish the candle.

    C)  The gas coming out of the delivery tube is heavier than air and will extinguish the candle.

    D)   The gas coming out of the delivery tube is lighter than air and will make the candle glow brightly.

    Correct Answer: C

    Solution :

      Carbon dioxide gas is formed when sodium bicarbonate reacts with conc. sulphuric acid to produce carbon dioxide \[2NaHC{{O}_{3}}+{{H}_{2}}S{{O}_{4}}\xrightarrow{{}}N{{a}_{2}}S{{O}_{4}}+2{{H}_{2}}O+2C{{O}_{2}}\] Since carbon dioxide is heavier than air, it starts filling the beaker and slowly reaches the level of the flame. As the gas does not support combustion, the flame is extinguished. The correct answer is C.


You need to login to perform this action.
You will be redirected in 3 sec spinner