Multiple Choice QuestionsIt is because of inability of ns2 electrons of the valence shell to participate in bonding that
Sn2+ is reducing while Pb4+ is oxidising
Sn2+ is oxidising while Pb4+ is reducing
Sn2+ and Pb2+ are both oxidising and reducing
Sn2+ and Pb2+ are both oxidising and reducing
A.
Sn2+ is reducing while Pb4+ is oxidising
Inability of ns2 electrons of the valence shell to participate in bonding on moving down the group in heavier p-block elements is called inert pair effect
As a result, Pb(II) is more stable than Pb(IV)
Sn(IV) is more stable than Sn(II)
∴ Pb(IV) is easily reduced to Pb(II)
∴ Pb(IV) is oxidising agent
Sn(II) is easily oxidised to Sn(IV)
∴ Sn(II) is reducing agent
The most suitable method of separation of 1 : 1 mixture of ortho and para-nitrophenols is
Sublimation
Chromatography
Crystallisation
Crystallisation
D.
Crystallisation
Steam distillation is the most suitable method of separation of 1: 1 mixture of ortho and para nitrophenols as there are intramolecular H-bonds in ortho nitrophenol.
Which of the following is a sink for CO?
Haemoglobin
Micro-organisms present in the soil
Oceans
Oceans
B.
Micro-organisms present in the soil
Micro-organisms present in the soil is a sink for CO
The reason for greater range of oxidation states in actinoids is attributed to
The radioactive nature of actinoids
Actinoid contraction
5f, 6d and 7s levels having comparable energies
5f, 6d and 7s levels having comparable energies
C.
5f, 6d and 7s levels having comparable energies
If molality of the dilute solution is doubled, the value of molal depression constant (Kf) will be
Doubled
Halved
Tripled
Tripled
D.
Tripled
Kf (molal depression constant) is a characteristic of solvent and is independent of molality.
Which one of the following statements is not correct?
Catalyst does not initiate any reaction
The value of equilibrium constant is changed in the presence of a catalyst in the reaction at equilibrium
Enzymes catalyse mainly bio-chemical reactions
Enzymes catalyse mainly bio-chemical reactions
B.
The value of equilibrium constant is changed in the presence of a catalyst in the reaction at equilibrium
A catalyst decreases activation energies of both the forward and backward reaction by the same amount, therefore, it speeds up both forward and backward reaction by the same rate. The equilibrium constant is therefore not affected by the catalyst at a given temperature.
Concentration of the Ag+ ions in a saturated solution of Ag2C2O4 is 2.2 ×10–4 mol L–1. Solubility product
2.42 × 10–8
2.66 × 10–12
4.5 × 10–11
4.5 × 10–11
D.
4.5 × 10–11
Which is the incorrect statement?
FeO0.98 has non stoichiometric metal deficiency defect
Density decreases in case of crystals with Schottky's defect
NaCl(s) is insulator, silicon is semiconductor,silver is conductor, quartz is piezo electric crystal
NaCl(s) is insulator, silicon is semiconductor,silver is conductor, quartz is piezo electric crystal
A.
FeO0.98 has non stoichiometric metal deficiency defect
D.
NaCl(s) is insulator, silicon is semiconductor,silver is conductor, quartz is piezo electric crystal
Frenkel defect occurs in those ionic compounds in which size of cation and anion is largely different.
The non-stoichiometric ferrous oxide is Fe0.93–0.96O1.00 and it is due to metal deficiency defect.
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