Melting Point of Ice (Determination) MCQs Quiz | Class 9
Class: IX | Subject: Science (Code 086) | Unit: Practicals (Unit I) | Topic: Melting Point of Ice (Determination). This quiz covers the procedure, observation, and definitions related to determining the melting point of ice. Attempt all 10 questions to test your knowledge, check your score, and download the answer key PDF for revision.
Overview: Melting Point of Ice
The melting point of a solid is defined as the temperature at which it changes its state from solid to liquid at atmospheric pressure. For pure water ice, this temperature is 0 degrees Celsius (273.15 Kelvin). During the melting process, the temperature remains constant until all the ice has turned into water. This constant temperature is due to the latent heat of fusion, which is the energy absorbed to overcome the forces of attraction between the particles without increasing the kinetic energy (temperature).
Key Procedure Points
- Preparation: Use crushed ice made from distilled water in a beaker. Crushed ice ensures better contact with the thermometer bulb.
- Thermometer Placement: The bulb of the thermometer must be completely surrounded by ice but should not touch the bottom or sides of the beaker to measure the ice temperature accurately, not the glass container.
- Stirring: Continuous stirring with a glass rod is essential to maintain a uniform temperature throughout the mixture.
- Observation: Record the temperature when it becomes steady and ice starts melting. It should remain at 0 degrees Celsius for some time.
Comparison: Melting vs Boiling
| Feature | Melting Point (Ice) | Boiling Point (Water) |
|---|---|---|
| Temperature | 0 degrees Celsius | 100 degrees Celsius |
| State Change | Solid to Liquid | Liquid to Gas |
| Impurity Effect | Lowers melting point | Elevates boiling point |
Common Errors to Avoid
Ensure the thermometer scale is readable and has a suitable least count (preferably 0.5 degrees C or 1 degree C). Do not use ice made from tap water as dissolved salts lower the melting point below 0 degrees Celsius. Parallax error should be avoided while reading the mercury level.
Extra Practice Questions
- What is the SI unit of temperature?
Answer: Kelvin (K). - Why does the temperature remain constant during melting?
Answer: Due to the Latent Heat of Fusion utilized to break intermolecular bonds. - If salt is added to ice, what happens to the melting point?
Answer: It decreases (freezing point depression). - What is the relation between Celsius and Kelvin?
Answer: K = Degree Celsius + 273.15. - Why is a glass stirrer used instead of a metal one?
Answer: Glass is a poor conductor of heat, preventing heat transfer from the surroundings to the ice through the stirrer.
Content created and reviewed by the CBSE Quiz Editorial Team based on the latest NCERT textbooks and CBSE syllabus. Our goal is to help students practice concepts clearly, confidently, and exam-ready through well-structured MCQs and revision content.