A compound having two direct bonds between P and H atoms is:
1.
2.
3.
4.
NH3 forms a hydrogen bond but PH3 does not because:
1. | Phosphorus is more electronegative as compared to nitrogen. |
2. | Nitrogen is more electronegative as compared to phosphorus. |
3. | Nitrogen and phosphorous have equal electronegativity. |
4. | Nitrogen is more stable as compared to phosphorus. |
Nitrogen exists as a diatomic molecule and phosphorus as P4 because on moving
1. | up a group, the tendency to form pπ−pπ bonds decreases. |
2. | down a group, the tendency to form pπ−pπ bonds decreases. |
3. | down a group, the tendency to form dπ−dπ bonds decreases. |
4. | up a group, the tendency to form dπ−dπ bonds decreases. |
Oxygen forms hydrogen bonds while chlorine does not, because :
1. | Chlorine has a bigger size and as a result, a higher electron density per unit volume. |
2. | Oxygen has a smaller size and as a result, a lower electron density per unit volume. |
3. | Oxygen has a smaller size and as a result, a higher electron density per unit volume. |
4. | Oxygen has a bigger size and as a result, a higher electron density per unit volume. |
1. | Neon gas is filled in discharge tubes with characteristic colours. |
2. | Neon gas is used in beacon lights. |
3. | Argon along with nitrogen is used in gas-filled electric lamps. |
4. | All of the above. |
Assertion (A): | The valency and oxidation number of sulphur in S8 respectively are 2 and 0. |
Reason (R): | S8 Rhombic is the most stable allotropic form of sulphur. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | The atomic size of F is smaller than that of Cl. |
Reason (R): | F-F bond is stronger than the Cl-Cl bond. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | (A) is false but (R) is true. |
Assertion (A): | NaCl reacts with concentrated H2SO4 to give colourless fumes with a pungent smell. But on adding MnO2, the fumes become greenish-yellow. |
Reason (R): | MnO2 oxidizes HCl to chlorine gas which is greenish-yellow. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | (A) is False but (R) is True. |
Assertion (A): | Both rhombic and monoclinic sulphur exist as S8 but oxygen exists as O2. |
Reason (R): | Oxygen forms pπ - pπ multiple bonds due to its small size and small bond length but pπ - pπ bonding is not possible in sulphur. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | Both (A) and (R) are False. |
(a) XeF6 + 3H2O →
(b) XeF6 + H2O
The products formed in the above reactions, respectively, are:
1. XeO3 , XeOF4
2. XeO6 , XeOF4
3. XeO3, XeOF6
4. XeO6 , XeOF6