|Class 11 Chemistry The S Block Elements||Biological importance of s-block elements|
Biological importance of s-block elements
Question. Draw the structure of (i) BeCl2 (vapour) (ii) BeCl2 (solid).
Question: Why is LiF almost insoluble in water whereas LiCl soluble not only in water but also in acetone?
Answer: Smaller size of fluoride ion due to which LiF has greater lattice energy than LiCI. Net change in energy during the dissolution of LiCI in water is more exothermic than dissolution of LiF in water. Solubility of LiCl in water and acetone is due to its low lattice energy and greater covalent character.
Question: Write balanced equations for reactions between
(a) Na2O2 and water
(b) KO2 and water
(c) Na2O and CO2
(a) 2 Na2O2(s) + 2 H2O(l) --> 4 NaOH(aq) + O2(g)
(b) 20 KO2 + H20 --> 20 KOH + 10 O2
(c) 2 Na2O + 3 Co2 --> 2 Na2Co3 + O2