1 |
Product fo combustion is. |
- A. C
- B. O2
- C. CO2
- D. All of these
|
2 |
Zince oxide is ............... solid substances. |
- A. Red
- B. White
- C. Yellow
- D. Blue
|
3 |
Compustion is a. |
- A. Physical Change
- B. Chemical change
- C. Thermal change
- D. None of these
|
4 |
Freezing of a liquid is a |
- A. Chemical change
- B. Chemicla property
- C. Physical change
- D. None of these
|
5 |
Silver+ hydrogen suolphide+Oxygen--------------- Silver sulphide + water The above reaction is known as. |
- A. Combustion
- B. Rusting
- C. Tarmishing
- D. Dehydration
|
6 |
Original colur or Nichrome wire is. |
- A. Silver grey
- B. Red hot
- C. White hot
- D. None of these
|
7 |
Rusting of iron takes place in the presence of. |
- A. Moisture
- B. O2
- C. Both moisture and O2
- D. Dry air
|
8 |
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
|
9 |
On heating sugar changes into |
- A. Carbon
- B. Water
- C. Both carbon and water
- D. Heat
|
10 |
A physical change occurs when. |
- A. Iron rusts
- B. Solution of common salt is heated
- C. A piece of wood burns
- D. Sygar us geated strongly
|