Advertisements
Advertisements
Question
Give the reason why the following is considered as chemical changes.
Copper carbonate on heat gives copper oxide and carbon dioxide.
Advertisements
Solution
Copper carbonate [CuCO3] green colour on heating gives copper oxide [Black colour CuO] and CO2.
Hence composition is changed new substances CuO [Black] and CO2 with new properties are produced and it is irreversible reaction hence it is a chemical change.
\[\ce{\underset{\text{Green}}{CuCO3} ->[\Delta] \underset{\text{Black}}{CuO} + CO2}\]
APPEARS IN
RELATED QUESTIONS
Fill in the blank.
A new substance is formed in a ............... change.
Melting of solid (wax) is a physical change.
Write short answer.
Name two reversible changes.
Solve this crossword by using the clues that follow.
Across
1. Energy in the form of sunlight is absorbed by the green plants in this process.
4. The reddish-brown substance formed over iron in the presence of oxygen and moisture.
5. This change is permanent and irreversible.
6. The process in which a solid directly changes into gaseous state.
Down
1. It is the change that takes place in case of swinging pendulum of a clock.
2. Occurrence of this is a non-periodic change as well as a natural change.
3. It is a physical change
State whether the following is physical or chemical changes.
cutting wood into small pieces —
True or false
Change of seasons is a non-periodic change.
Write true or false
Decomposition of leaves is a fast change.
Change is the law of nature and occurs in our everyday life, at all times and in all places.
Differentiate between the following change with a suitable example.
Natural and man-made change.
Ice kept in a beaker, slowly melts and turns into water. The water in the beaker on solidification is freezing turns back to ice. Give four reasons why the change from ice to water and water back to ice is considered a physical change.
Give a reason why
Change of seasons is a periodic change while the change of weather is a non-periodic change.
