Give reasons for the following.
a. LiCI is more covalent than KCI.
b. LiI has lower melting point than LiF.
c. During electrolysis of molten sodium chloride, calcium chloride and potassium fluoride are added.

The melting point of sodium chloride is more than that of sodium. Justify.

(a) Given reasons for the following : (i) Bond enthalpy of F_2 is lower than that of Cl_2 . (ii) PH_3 has lower boiling point than NH_3 . (b) Draw the structures of the following molecules : (i) BrF_3 (ii) (HPO_3)_3 (iii) XeF_4

Which of the following is/are correct statements? (A) The melting point of Lithium is more than that of sodium (B) The density of sodium is more than those of both Lithium and potassium (C) The melting point of caesium (CS) is lowest in Alkali group (D) Alkali metals have maximum atomic radius in their period

Write the balanced chemical equations for the following reaction. (a) Sodium carbonate on reaction with hydrochloric acid in equal molar concentrations gives sodium chloride and sodium hydrogen carbonate. (b) Sodium hydrogen carbonate on reaction with hydrochloric acid gives sodium chloride, water and liberates carbon dioxide. (c) Copper sulphate on treatment with potassium iodide precipitates cuprous iodide iodide (Cu_(2)I_(2)) , liberates iodine gas and also forms potassium sulphate.