The correct sequence of increasing radii is -
1. | Ar < K+ < Ca2+ | 2. | Ca2+ < Ar < K+ |
3. | Ca2+ < K+ < Ar | 4. | K+ < Ar < Ca2+ |
The formation of the oxide ion O2-(g), from oxygen atom requires first an exothermic and
then an endothermic step as shown below,
Thus, process of formation of O2- in gas phase is unfavourable even though O2- is
isoelectronic with neon. It is due to the fact that
1. electron repulsion outweighs the stability gained by achieving noble gas configuration
2. O- ion has comparatively smaller size than oxygen atom
3. Oxygen is more electronegative
4. addition of electron in oxygen result in large size of the ion
Be2+ is isoelectronic with which of the following ions?
1. H+
2. Li+
3. Na+
4. Mg2+
The ease of adsorption of the hydrated alkali metal ions on an ion-exchange resins
follows the order
1. Li+<K+<Na+<Rb+
2. Rb+<K+<Na+<Li+
3. K+<Na+<Rb+<Li+
4. Na+<Li+<K+<Rb+
The correct order of the decreasing ionic radii among the following isoelectronic species is :
1. Ca2+ > K+ > S2- > Cl-
2. Cl- > S2- > Ca2+ > K+
3. S2- > Cl- > K+ > Ca2+
4. K+ > Ca2+ > Cl- > S2-
The correct order of increasing electron gain enthalpy with a negative sign for the elements O, S, F, and Cl is :
1. Cl < F < S < O
2. O < S < F < Cl
3. F < S < O < Cl
4. S < O < Cl < F
Which one of the following compounds is a peroxide ?
1. KO2
2. BaO2
3. MnO2
4. NO2
The sequence of ionic mobility in aqueous solution is
(1) K+>Na+>Rb+>Cs+
(2) Cs+>Rb+>K+>Na+
(3) Rb+>K+>Cs+>Na+
(4) Na+>K+>Rb+>Cs+
Which one of the following arrangements does not give the correct picture of the trends indicated against it?
(1) F2 > Cl2 > Br2 > I2 :Oxidising power
(2) F2 < Cl2 > Br2 > I2 : Electron gain enthalpy
(3) F2 > Cl2 > Br2 > I2 : Bond dissociation energy
(4) F2 > Cl2 > Br2 > I2: Electronegativity
Identify the correct order of the size of the following:
(1) Ca2+<K+<Ar<S2-<Cl-
(2) Ca2+<K+<Ar<Cl-<S2-
(3) Ar<Ca2+<K+<Cl-<S2-
(4) Ca2+<Ar<K+<Cl-<S2-