| 1 |
A piece of iron is kept in open air for 5 days. A film of corrosion formed over it is. |
- A. Iron oxide
- B. Iron sulphide
- C. Iron Chloride
- D. Iron Hydride
|
| 2 |
What are teh products when electric current is passed through water. |
- A. Only steam
- B. Hydrogen and steam
- C. Hydrogen and oxygen
- D. Oxygen and steam
|
| 3 |
Chemical reaction of oxygen with other substances is called. |
- A. Oxidation
- B. Reduction
- C. Rusting
- D. None of these
|
| 4 |
During combustion, a substance reacts with |
- A. Hydrogen
- B. Water
- C. Oxygen
- D. Carbon di oxide
|
| 5 |
Rusting of iron takes place in the presence of. |
- A. Moisture
- B. O2
- C. Both moisture and O2
- D. Dry air
|
| 6 |
Zince oxide is ............... solid substances. |
- A. Red
- B. White
- C. Yellow
- D. Blue
|
| 7 |
What happens to water on heating. |
- A. Evaporates
- B. Condense
- C. Freez
- D. None of these
|
| 8 |
The temperature at which a liquid's vapour pressure is equal to the external pressure surrounding the liquid is. |
- A. Melting point
- B. Boiling point
- C. Freezing point
- D. Highest temperature.
|
| 9 |
Freezing of a liquid is a |
- A. Chemical change
- B. Chemicla property
- C. Physical change
- D. None of these
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| 10 |
Select all that happen during a chemicla change. |
- A. A temporary chagne occurs.
- B. Composition of the substanes is changed.
- C. Propertis of the sbstances are changed.
- D. New substances with different properties are formed.
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