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प्रश्न
Give the reason why the following is considered as chemical changes.
Copper carbonate on heat gives copper oxide and carbon dioxide.
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उत्तर
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.
\[\ce{\underset{\text{Green}}{CuCO3} ->[\Delta] \underset{\text{Black}}{CuO} + CO2}\]
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संबंधित प्रश्न
Tick the most appropriate answer.
3. Physical changes are
- permanent.
- periodic,
- temporary
- irreversible.
State whether the following is physical or chemical changes.
burning of sugar —
State whether the following is physical or chemical changes.
mixing oil with water —
Write true or false
Burning of paper and formation of curd are reversible changes.
Classify the following as a physical or a chemical change.
Drying of wet clothes
Classify the following as a physical or a chemical change.
Manufacture of salt from sea water
Classify the Following as a Physical Or a Chemical Change.
Making of a Sugar Solution
Fill in the blank.
There is no change in the _____________of the substance during a physical change.
Select the chemical changes from the following list of changes
Change of seasons
Match the items of Column I with the items of Column II.
| Column I | Column II | ||
| (a) | Large crystals | (i) | Turns lime water into milky |
| (b) | Depositing a layer of zinc on iron | (ii) | Physical change |
| (c) | Souring of milk | (iii) | Rust |
| (d) | Carbon dioxide | (iv) | Sugar candy (Mishri) |
| (e) | Iron oxide | (v) | Chemical change |
| (f) | Dissolving common salt in water | (vi) | Galvanisation |
