Advertisements
Advertisements
प्रश्न
Select the chemical changes from the following list of changes
The occurrence of lightning.
Advertisements
उत्तर
Occurance of lightening is a CHEMICAL change, energy is produced, a new substance with new properties is produced.
APPEARS IN
संबंधित प्रश्न
Classify the following as chemical or physical change:
Rusting of almirah
Tick the most appropriate answer.
Rising and setting of the sun at a given place is a
Which of the following are physical changes and which are chemical changes ?
Glowing of an electric bulb
Classify the following as a physical or a chemical change.
Melting of wax
Given reason:
Cutting of a cloth piece is a physical change, though it cannot be reversed.
Match the examples of changes in List I with the correct.
| List I | List II |
| 1. Expansion of a steel rod on heating | A: Physical change |
| 2. Rotting of eggs | B: Chemical change |
| 3. Milk turning sour | |
| 4. Tarnishing of copper | |
| 5. Separation of naphthalene from a mixture of naphthalene and sodium chloride. |
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.
State which of the following 1 to 5 pertain to – A: Physical Change B: Chemical change :
- Sublimation.
- Fermentation.
- Liquefaction or condensation.
- Magnetization.
- Respiration.
Natural changes which take place in nature on their own, are beyond the control of human being.
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 |
