Class 11th

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The element from group 2 is beryllium. Be (OH)₂ is amphoteric. It reacts with both acids and bases. It reacts with acid to form beryllium chloride and it reacts with base to form beryllate 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

Beryllium sulfate are readily soluble in water.

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59.  (i) → (a); (ii) → (b); (iii) → (b) : (iv) → (c)

This is a short answer type question as classified in NCERT Exemplar

These two elements have similar properties because of their similar atomic and ionic radii.

(i) Both are lighter element and harder than the other metals in their respective groups.

(ii) The halides of both elements, LiCl and MgCl₂ are soluble in ethanol.

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58. (i) →   (a); (ii) →   (a); (iii) →   (b)

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(i) O₂²⁻+ 2H₂O → H₂O₂+2OH⁻

(ii) 2O₂⁻+2H₂O→2OH⁻+H₂O₂+O₂

vvvvvvvvvvvvvvvvv

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

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Alkali metals forms oxide when reacted with air. Lithium forms monoxide, sodium forms peroxide and potassium forms superoxide.

4Li+O₂→2Li₂O

Na+O₂→Na₂O₂

 K+O₂→KO₂

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Lithium has the highest negative reduction potential value. Due to the small size of lithium it has the highest ionization enthalpy. Due to this, the reducing power of lithium is the highest in an aqueous solution.

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