Assertion: All halogens are coloured.
Reason: The halogens absorb visible light.
If both assertion and reason are true and the reason is a correct explanation of the assertion.
If both the assertion and reason are true but the reason is not a correct explanation of the assertion.
If the assertion is true but the reason is false.
If both the assertion and reason are false.
A.
If both assertion and reason are true and the reason is a correct explanation of the assertion.
All the halogens are coloured. The colour deepens with the rise of atomic number from fluorine to iodine.
The colour is due to the absorption of energy from visible light by their molecules or excitation of outer electrons to higher energy levels.
F | Cl | Br | I |
Light yellow | Yellow green | Reddish brown | Deep violet |
Assertion: F-F bond has low bond dissociation energy.
Reason: The fluorine has lower reactivity.
If both assertion and reason are true and reason is a correct explanation of the assertion.
If both the assertion and reason are true but the reason is not a correct explanation of the assertion.
If the assertion is true but the reason is false.
If both the assertion and reason are false.
Assertion: Dinegative anion of oxygen (O2-) is quite common but negative anion of sulphur (S2-) is less common.
Reason: Covalency of oxygen is two.
If both assertion and reason are true and the reason is a correct explanation of the assertion.
If both the assertion and reason are true but the reason is not a correct explanation of the assertion.
If the assertion is true but the reason is false.
If both the assertion and reason are false.
In the brown ring complex [Fe(H2O)5(NO)]SO4, nitric oxide behaves as:
NO+
neutral NO molecule
NO-
NO2-
The hydrides of the first elements in groups 15-17, namely NH3, H2O and HF respectively show abnormally high values for melting and boiling points. This is due to
small size of N, O and F
the ability to form extensive intermolecular H-bonding
the ability to form extensive intramolecular H-bonding
effective van der Waals' interaction
Roasting of sulphides gives the gas X as a by-product. This is a colourless gas with choking smell of burnt sulphur. and causes great damage to respiratory organs as a result of acid rain. Its aqueous solution is acidic acts as a reducing agent and its acid has never been insolated. The gas X is
H2S
SO2
CO2
SO3
Among the following observations, the correct one that differentiates between SO and SO is
both form precipitate with BaCl2, SO dissolves in HCl but SO does not
SO forms precipitate with BaCl2, SO does not
SO forms precipitate with BaCl2, SO does not
both form precipitate with BaCl2, SO dissolves in HCl but SO does not
Which one of the following is not true at room temperature and pressure?
P4O10 is white solid
SO2 is a colourless gas
SO3 is a colourless gas
NO2 is a brown gas