NEET and AIPMT NEET Chemistry The p-Block Elements (XII) MCQ Questions Solved


The species that does not contain peroxide ions is:

(a) PbO2

(b) H2O2

(c) SrO2

(d) BaO2

(a) PbO2 does not contain -O-O- bond. It is lead dioxide.

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Which of the following on heating produces NO2?

(1) NaNO3

(2) AgNO3

(3) NH4NO3

(4) NH4NO2

(b)AgNO3   Ag++ ½ O2 + NO2

2NaNO3  500°C 2NaNO2 + O2

4NaNO3   800°C  2Na2O + 5O2 + 2N

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The dissolution of Al(OH)3 by a solution of NaOH results in the formation of:

(1) [Al(H2O)4(OH)2]+

(2) [Al(H2O)3(OH)3]

(3) [Al(H2O)2(OH)4]-

(4) [Al(H2O)6(OH)3]

(3) Al(OH)3 dissolves in NaOH solution to give Al(OH)4- ion which is supposed to have the octahedral complex species [Al(OH)4(H2O)2]- in aqueous solution.

Al(OH)3 + NaOH(aq)  [Al(OH)4(H2O)2]-(aq) + NaOH+(aq)

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The formation of PH+4 is difficult compared to NH+4 because

(1) lone pair of phosphorous is optically inert

(2) lone pair of phosphorous resides in almost pure p- orbital

(3) lone pair of phosphorous resides at sp3 orbital

(4) lone pair of phosphorous resides in almost pure s- orbital

(4) PH3..+H+ PH+4

According to Drago's rule lone pair on phosphorous resides in almost pure s- orbital, hence due to non directional nature, its overlapping tendency is greatly reduced in comparison to a lone pair present in hybrid orbital, which is directional as present in NH3..

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Concentrated nitric acid reacts with iodine to give:

(1) HOI

(2) HI

(3) HOIO2

(4) HOIO3

(3) I2 + 10HNO3   2HIO3 + 10NO2 + 4H20

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Hydrolysis of one mole of peroxodi-sulphuric acid produces:

(1) two moles of sulphuric acid

(2) two moles of peroxomono-sulphuric acid

(3) one mole of sulphuric acid, one mole of peroxomono-sulphuric acid

(4) one mole of sulphuric acid, one mole of peroxomono-sulphuric acid and one mole of hydrogen peroxide

(3)OH-SOO-O-O-SOO-OH +H2OOH-SOO-OH+H-O-SOO-O-H

                                   (sulphuric acid)              (Peroxomono-sulphuric acid)

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Anhydrous aluminium chloride (Al2Cl6) is covalent compound and soluble in water giving:

(a)Al3+ and Clions

(b)[Al(H2O)6]3+ and  Clions

(c)[AlCl2 (H2O)4]+ and [AlCl(H2O)2]- ions

(c) AlCl3.6H2dissociation [AlCl2 (H2O)4]- +[AlCl(H2O)2]-

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Which of the following is the correct statement?

(1) F2 has higher dissociation energy than Cl2

(2) F has higher electron affinity than Cl

(3) HF is stronger acid than HCl

(4) Boiling point increases down the group in halogens

(4)

(1)-Bond dissociation energy of F2 is less than that of Cl2

(2)-Cl has higher E.A. than fluorine

(3)-HF is weaker acid than HCl, due to higher bond energy

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Incorrectly matched characteristic is:

(a) S8: covalent lattice

(b) P4: tetrahedron

(c) S42-: zigzag

(d) SiO2: Covalent lattice

(a) S8: Molecular solid, in solid sulphur various S8 molecules are bonded to one another by weak molecular forces

SiO2:represents to 3D silicate, that has covalent lattice as one silicon atom is bonded to four oxygen atom in turn Bonded to two silicon.

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Among the following compounds, which on heating do not produce N2?

(1) (NH4)2Cr2O7

(2) NH4Cl+NaNO2

(3) NH4Cl+CaO

(4) Ba(N3)2

(c) NH4Cl+ NaNO2→NH4NO2+NaCl
NH4NO2  N2↑ +2H2O

Ba(N3)2 →Ba+3N2↓ 
2NH4Cl+CaO→CaCl2+2NH3↑+H2O)

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