Amongst the following, select the element having highest ionization enthalpy.

• Sodium

• Potassium

• Beryllium

• Magnesium

2.

The main oxides formed on combustion of Li, Na and K in excess of air are, respectively:

• LiO₂, Na₂O₂ and K₂O

• LiO₂, Na₂O₂ and KO₂

• LiO, Na₂O₂ and KO₂

• LiO, Na₂O₂ and KO₂

Which one of the following alkaline earth metal sulphates has its hydration enthalpy greater than its lattice enthalpy?

• CaSO₄

• BeSO₄

• BaSO₄

• BaSO₄

The correct statement for the molecule, CsI₃ is 

• It is a covalent molecules

• It contains Cs⁺ and I₃^-

• It contains Cs³⁺ and I^- ions

• It contains Cs³⁺ and I^- ions

Which of the following on thermal decomposition yields a basic as well as an acidic oxide?

• NaNO₃

• KClO₃

• CaCO₃

• CaCO₃

Both lithium and magnesium display several similar properties due to the diagonal relationship; however, the one which is incorrect is :

• Both form basic carbonates

• Both form soluble bicarbonates

• Both form nitrides

• Both form nitrides

When BaCl₂ is added to an aqueous salt solution, a white precipitate is obtained. The anion among CO${}_3^{2-}$-, SO${}_3^{2-}$- and SO${}_4^{2-}$ that was present in the solution can be

• CO${}_3^{2-}$ but not any of the other two

• SO${}_3^{2-}$ but not any of the other two

• SO${}_4^{2-}$ but not any of the other two

• Any of them

Match the flame colours of the alkaline earth metal salts in the Bunsen burner.

A. Calcium	p. Brick red
B. Strontium	q. Apple green
C. Barium	r. Crimson

• A - p; B - r; C - q

• A - r; B - p; C - q

• A - q; B ; r; C - p

• A - p; B - q; C - r

Which of the following statement(s) is (are) correct when a mixture of NaCl and K₂Cr₂O₇ is gently warmed with conc. H₂SO₄?

• A deep red vapour is evolved

• The vapour when passed through NaOH solution, gives a yellow solution

• Chlorine gas is also evolved

• Chromyl chloride is formed

Addition of sodium thiosulphate solution to a solution of silver nitrate gives X as white precipitate, insoluble in water but soluble in excess thiosulphate solution to give Y. On boiling in water, Y gives Z. X, Y and Z respectively are

• Ag₂S₂O₃, Na₃[Ag(S₂O₃)₂], Ag₂S

• Ag₂SO₄, Na[Ag(S₂O₃)₂], Ag₂S₂

• Ag₂S₂O₃, Na₅[Ag(S₂O₃)₃], AgS

• Ag₂SO₃, Na₃[Ag(S₂O₃)₂], Ag₂O