1
AIEEE 2004
MCQ (Single Correct Answer)
+4
-1
Which one of the following sets of ions represents the collection of isoelectronic species? (Atomic nos. : F = 9, Cl = 17, Na = 11, Mg = 12, Al = 13, K = 19, Ca = 20, Sc = 21)
A
K+, Cl-, Mg2+, Sc3+
B
Na+, Ca2+, Sc3+, F-
C
K+, Ca2+, Sc3+, Cl-
D
Na+, Mg2+, Al3+, Cl-
2
AIEEE 2004
MCQ (Single Correct Answer)
+4
-1
Which one of the following ions has the highest value of ionic radius?
A
O2-
B
B3+
C
Li+
D
F-
3
AIEEE 2004
MCQ (Single Correct Answer)
+4
-1
Among Al2O3, SiO2, P2O3 and SO2 the correct order of acid strength is
A
SO2 < P2O3 < SiO2 < Al2O3
B
Al2O3 < SiO2 < P2O3 < SO2
C
Al2O3 < SiO2 < SO2 < P2O3
D
SiO2 < SO2 < Al2O3 < P2O3
4
AIEEE 2004
MCQ (Single Correct Answer)
+4
-1
The formation of the oxide ion O2-(g) requires first an exothermic and then an endothermic step as shown below

O(g) + e- = $$O_{(g)}^{-}$$ $$\Delta $$Ho = -142 kJmol-1

$$O_{(g)}^{-}$$ + e- = $$O_{(g)}^{2-}$$ $$\Delta $$Ho = 844 kJmol-1

This because
A
O- ion will tend to resist the addition of another electron
B
Oxygen has high electron affinity
C
Oxygen is more electronegative
D
O- ion has comparatively larger size than oxygen atom
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