Physics Class 9 Practical 20 Important Viva Questions with Answers (ice is converted into water )

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 PRACTICAL 20

To draw a graph between temperature and time when ice is converted into water and then to steam by slow heating..

VIVA VOCE

 

  1. What is the objective of this experiment?

    • To draw a graph between temperature and time when ice is converted into water and then to steam by slow heating.

  2. What are the different phases observed in this experiment?

    • The phases are solid (ice), liquid (water), and gas (steam).

  3. At what temperature does ice start to melt?

    • Ice starts to melt at 0°C.

  4. What happens to the temperature during the phase change from ice to water?

    • The temperature remains constant at 0°C during the phase change from ice to water.

  5. What is the latent heat of fusion?

    • The latent heat of fusion is the amount of heat required to change 1 kg of ice at 0°C to water at 0°C without any change in temperature.

  6. At what temperature does water start to boil?

    • Water starts to boil at 100°C.

  7. What happens to the temperature during the phase change from water to steam?

    • The temperature remains constant at 100°C during the phase change from water to steam.

  8. What is the latent heat of vaporization?

    • The latent heat of vaporization is the amount of heat required to change 1 kg of water at 100°C to steam at 100°C without any change in temperature.

  9. Why is it important to heat the ice slowly in this experiment?

    • Slow heating ensures that the temperature changes gradually and allows for accurate measurement of the phase changes.

  10. How would the graph look during the phase changes?

    • The graph will show horizontal lines (plateaus) during the phase changes (0°C for ice to water and 100°C for water to steam), indicating that the temperature remains constant during these transitions.

  11. What is the significance of the plateaus in the temperature-time graph?

    • The plateaus represent the phase changes where heat is absorbed without a change in temperature.

  12. What is the difference between latent heat and sensible heat?

    • Latent heat is the heat absorbed or released during a phase change at constant temperature, while sensible heat is the heat absorbed or released that causes a change in temperature without a phase change.

  13. Can you explain the concept of specific heat capacity?

    • Specific heat capacity is the amount of heat required to raise the temperature of 1 kg of a substance by 1°C.

  14. How can you ensure accurate temperature readings in this experiment?

    • Use a calibrated thermometer, ensure proper placement in the substance, and avoid rapid heating or cooling.

  15. What precautions should be taken while performing this experiment?

    • Handle the hot apparatus carefully, avoid rapid heating, ensure accurate and timely measurements, and maintain a clean working environment.