Amongst the following, select the element having highest ionization enthalpy.
Sodium
Potassium
Beryllium
Magnesium
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
B.
It contains Cs+ and I3-
I3- is an ion made up of I2 and I- which has linear shape
While Cs+ is an alkali metal cation.
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-, SO- and SO that was present in the solution can be
CO but not any of the other two
SO but not any of the other two
SO 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
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
Among the following compounds, the one(s) that gives (give) effervescence with aqueous NaHCO3 solution is (are)
(CH3CO)2 O CH3COOH PhOH CH3COCHO
I II III IV
I and II
I and III
Only II
I and IV