Which of the following oxides is most acidic in nature?

1. MgO

2. BeO

3. BaO

3. CaO

On heating which of the following releases CO₂ most easily?

1. ${\mathrm{K}}_2{\mathrm{CO}}_3$

2. ${\mathrm{Na}}_2{\mathrm{CO}}_3$

3. ${\mathrm{MgCO}}_3$

4. ${\mathrm{CaCO}}_3$

Which one of the alkali metals forms only, the normal oxide, M₂O on heating in air?

1. Rb

2. K

3. Li

4. Na

The ease of adsorption of the hydrated alkali metal ions on ion-exchange resins follows the order

1. ${\mathrm{Li}}^{+}<{\mathrm{K}}^{+}<{\mathrm{Na}}^{+}<{\mathrm{Rb}}^{+}$

2. ${\mathrm{Rb}}^{+}<{\mathrm{K}}^{+}<{\mathrm{Na}}^{+}<{\mathrm{Li}}^{+}$

3. ${\mathrm{K}}^{+}<{\mathrm{Na}}^{+}<{\mathrm{Rb}}^{+}<{\mathrm{Li}}^{+}$

4. ${\mathrm{Na}}^{+}<{\mathrm{Li}}^{+}<{\mathrm{K}}^{+}<{\mathrm{Rb}}^{+}$

Which of the following compounds has the lowest melting point?

1.  ${\mathrm{CaBr}}_2$

2.  ${\mathrm{Cal}}_2$

3.  ${\mathrm{CaF}}_2$

4.  ${\mathrm{CaCl}}_2$

Which of the following alkaline earth metal sulphates has hydration enthalpy higher than the lattice enthalpy?

1. ${\mathrm{CaSO}}_4$

2. Mg${\mathrm{SO}}_4$

3. ${\mathrm{BaSO}}_4$

4. ${\mathrm{SrSO}}_4$

Property of the alkaline earth metals that increases with their atomic number

1. Solubility of their hydroxides in water

2. Solubility of their sulphates in water

3. Ionization energy

4. Electro-negativity