The S-block Elements

This is a matching type question as classified in NCERT Exemplar

(i) → (f); (ii) → (d); (iii) → (b) : (iv) → (c) ; (v) → (e); (vi) → (a)

All alkali metal and alkaline earth metals except beryllium and magnesium gives characteristic color when introduced into flame. Due to released energy being absorbed in the visible region, alkali metals and alkaline earth metals gives characteristic color.

(i) Caesium imparts blue color when introduced into flame.

(ii) Sodium imparts yellow color when introduced into flame.

(iii) Potassium imparts violet color when introduced into flame.

(iv) Calcium imparts brick red color when introduced into flame.

(v) Strontium imparts crimson red color when introduced into flame.

(vi) Barium imparts apple green color when introduced into flame.

(iv) Calcium imparts brick red color when introduced into flame.

(v) Strontium imparts crimson red color when introduced into flame.

(vi) Barium imparts apple green color when introduced into flame.

This is a matching type question as classified in NCERT Exemplar

(i) → (c); (ii) → (b); (iii) → (d) : (iv) → (a); (e)

(i) Lithium has the highest negative reduction potential value. Due to the small size of lithium it has a small atomic size, the highest ionization enthalpy Due to this, the reducing power of lithium is the highest.

(ii) Sodium is a stronger monoacidic base due to lower first ionization enthalpy of sodium. Also sodium forms sodium hydroxide  Therefore 1 mole of it replaces one mole of hydrogen ions from acids.

(iii) Calcium oxalate is an ionic compound because its hydration enthalpy is low. It is highly insoluble and dissolves poorly in water.

(iv) Barium sulfate is insoluble due to the high hydration energy. The electronic configuration of barium is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 6s²

Thus, option (iv) from column I is matched with (a) and (e) from column II.

This is a multiple choice type question as classified in NCERT Exemplar

Correct option (i) and (ii)

Beryllium resembles aluminum through the diagonal relation. Beryllium forms a protective film of oxide on the surface, and thus, is prevented by the attack of acids.

Thus, statement (1) is correct.

On moving down the group, as the size increases the hydration enthalpy decreases. The hydration enthalpy of beryllium ions are high due to the small size. Thus, sulfates are readily soluble in water. Thus, statement (2) is correct.

Beryllium does not exhibit coordination numbers more than four. As it has no d orbitals.

Thus, statement (3) is not correct.

Beryllium oxide is amphoteric in nature. It reacts with both acids and bases. It reacts with acid to form beryllium chloride and it reacts with base to form becyllate ion which is soluble in sodium hydroxide. The reaction is shown below.

Be (OH)₂+2OH−→ [Be (OH)₄]²⁻

Be (OH)₂+2HCl→BeCl₂+2H₂O

Thus, statement (4) is not correct.