| 1 |
Bone ash contain calcium phosphate |
- A. 40%
- B. 50%
- C. 70%
- D. 80%
|
| 2 |
When Cu reacts with conc. HNO3 , which one of the following gases is evolved |
- A. N2O
- B. NO
- C. NO2
- D. N2O5
|
| 3 |
Which of the following specie has the maximum number of unpaired electrons. |
- A. O2
- B. O2+
- C. O2-
- D. O2<sup>-2</sup>
|
| 4 |
Out of all the elements of groups VI-A the highest melting and boiling points is shown by the element |
|
| 5 |
Which one of the following oxide is brown in colour. |
- A. NO
- B. NO2
- C. N2O
- D. N2O3
|
| 6 |
Maximum number of unpaired electrons is in |
- A. O<sub>2</sub>
- B. O<sub>2</sub><sup>+</sup>
- C. O<sub>2</sub><sup>-</sup>
- D. O<sub>2</sub><sup>2-</sup>
|
| 7 |
When concentrated H2SO4 and solid sodium chloride react together at room temperature the product are. |
- A. Two salts only
- B. A salt and a base
- C. A salt and an acid
- D. A salt and water
|
| 8 |
Which allotrope of phosphorus has layers like graphite. |
- A. white phosphorus
- B. Red phosphorus
- C. Black Phosphorus
- D. Amorphous phosphorus
|
| 9 |
NH4NO3 on heating at 200 <sup>o</sup>C changes to |
- A. N2O
- B. NO
- C. NO2
- D. N2O4
|
| 10 |
The brown gas formed when metal reduces HNO3 is |
- A. N2O5
- B. N2O3
- C. NO2
- D. NO
|