s-Block Elements · Question 21

In Castner-Kellner cell for production of sodium hydroxide

1. brine is electrolyzed using graphite electrodes
2. molten sodium chloride is electrolysed
3. sodium amalgam is formed at mercury cathode
4. brine is electrolyzed with Pt electrodes

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 an ion-exchange resin follows the order :

1. Li+ < K+ < Na+ < Rb+
2. Rb+ < K+ < Na+ < Li+
3. K+ < Na+ < Rb+ < Li+
4. Na+ < Li+ < K+ < Rb+

Which of the following statements is incorrect?

1. Pure sodium metal dissolves in liquid ammonia to give blue solution.
2. NaOH reacts with glass to give sodium silicate.
3. Aluminium reacts with excess NaOH to give Al(OH)3.
4. NaHCO3 on heating gives Na2CO3.

Match List-I with List-II for the compositions of substances and select the correct answer using the codes given below.

1. (A)-(iii), (B)-(iv), (C)-(i), (D)-(ii)
2. (A)-(ii), (B)-(iii), (C)-(iv), (D)-(i)
3. (A)-(i), (B)-(ii), (C)-(iii), (D)-(iv)
4. (A)-(iv), (B)-(iii), (C)-(ii), (D)-(i)

Which one of the following is present as an active ingredient in bleaching powder for bleaching action?

1. CaOCl2
2. Ca(OCl)2
3. CaO2Cl
4. CaCl2

The compound A on heating gives a colourless gas and a residue that is dissolved in water to obtain B. Excess of CO2 is bubbled through aqueous solution of B, C is formed which is recovered in the solid form. Solid C on gentle heating gives back A. The compound is

1. CaCO3
2. Na2CO3
3. K2CO3
4. CaSO4 2H2O

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

1. CaSO4
2. BeSO4
3. BaSO4
4. SrSO4

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. electronegativity

Which one of the following compounds is a peroxide?

1. KO2
2. BaO2
3. MnO2
4. NO2