Advertisements
Advertisements
प्रश्न
State one instance where water undergoes a physical change and one in which it undergoes a chemical change.
Advertisements
उत्तर
Water undergoes a physical change when it is heated to a temperature of 100°C. At this temperature, the water gets converted to water vapours. This process is called evaporation. Water undergoes a chemical change when it is subjected to electricity. It splits into its constituents, oxygen and hydrogen, by the process of electrolysis.
APPEARS IN
संबंधित प्रश्न
Write short answer.
What are man-made changes ?
What role does energy play in initiating a chemical change ?
State whether the following is physical or chemical changes.
respiration in living beings —
Write true or false
Melting of ice is a physical change.
Classify the following as a physical or a chemical change.
Burning of coal
Classify the Following as a Physical Or a Chemical Change.
Making of a Sugar Solution
State why addition of sodium chloride to water is considered a physical change, while addition of dilute sulphuric acid to zinc is considered a chemical change.
Potassium chloride is added to water and stirred. A salt solution is obtained, which is then boiled, leaving behind a residue.
- Is the above change physical or chemical?
- Name the residue which remains behind after the salt solution is boiled.
- Is the change reversible or not reversible?
- Are the composition and properties of the original substance altered?
- Give a reason why the above experimentation would not be possible if calcium carbonate was taken in place of potassium chloride.
Give the reason why the following is considered as chemical changes.
Copper carbonate on heat gives copper oxide and carbon dioxide.
Assertion: Burning of wood log to charcoal is a physical change.
Reason: The products formed of burning a piece of wood can be easily converted back to wood log.
