Multiple Choice QuestionsIn the extraction of copper from its sulphide ore, the metal finally obtained by the reduction of cuprous oxide with
Iron (II) sulphide
Carbon monoxide
Copper (I) sulphide
Copper (I) sulphide
C.
Copper (I) sulphide
Reduction of Copper oxide done with Copper (I) sulphide.
Cu2S + 2Cu2O → 6Cu +SO2 ↑
Number of possible isomers for the complex [Co(en)2Cl2]Cl will be
(en =ethylenediamine)
2
1
3
3
C.
3
[Co(en)2Cl2]Cl
Possible isomers are
Hence,total number of stereoisomers = 2+1 = 3
The stability of +1 oxidation state among Al, Ga, In and TI increases in the sequence
Ga<In< Al<Tl
Al<Ga<In<Tl
Tl<In<Ga<Al
Tl<In<Ga<Al
B.
Al<Ga<In<Tl
Al< Ga< In <Tl
This is due to inert pair effect or tendency of ns2 electrons do not participate in bond formation.
This tendency decreases on moving down the group.
The variation of the boiling point of the hydrogen halides in the order HF > HI > HBr > HCl. What explains the higher boiling point of hydrogen fluoride?
The electronegativity of fluorine is much higher than for other elements in the group
There is strong hydrogen bonding between HF molecules
The bond energy of HF molecules is greater than in other hydrogens halides
The bond energy of HF molecules is greater than in other hydrogens halides
B.
There is strong hydrogen bonding between HF molecules
There is a strong hydrogen bonding between HF molecules. Hence, the boiling point is highest for HF.
HF > HI > HBr > HI
The rate of constant of the reaction A → B is 0.6 x 10-3 mole per second. If the concentration of A is 5 M then concentration of B after 20 min is
1.08 M
3.60 M
0.36 M
0.36 M
D.
0.36 M
For a zero -order reaction unit of the rate constant is mole per second. Hence, we can easily calculate concentration of B after 20 min by the following formula,
x = Kt
x = Kt = 0.6 x 10-3 x 20 x 60 = 0.72 M
Assuming complete ionisation, same moles of which of the following compounds will require the least amount of acidified KMnO4 for complete oxidation?
FeSO4
FeSO3
FeC2O4
FeC2O4
A.
FeSO4
FeSO4 will require the least amount of acidified KMnO4 for complete oxidation.
The sum of coordination number and oxidation number of the metal M in the complex [M(en)2(C2O4)]Cl (where en is ethylenediamine) is
9
6
7
7
B.
6
Given complex compound is [M(en)2(C2O4)]Cl
Let oxidation number of M is x
therefore, x- 2 - 2 = -1
x = +3
Now, as coordination number is defined as the total number of binding sites attached to the metal.Hence, in the given complex coordination number is 6.
The name of complex ion, [Fe(CN)6]3- is
hexacyanoiron (III) ion
hexacyanitoferrate (III) ion
tricyanoferrate (III) ion
tricyanoferrate (III) ion
D.
tricyanoferrate (III) ion
When complex- ions is an anion, the name of the metal ends with the suffix -ate along with its oxidation number in the complex- ion.
[Fe(CN)6]3- = Hexacyanidoferrate (III) ion
The correct statement regarding defects in the crystalline solid is
Schottky defects have no effect on the density of crystalline solid
Frenkel defect decreases the density of crystalline solids
Frenkel defect is a dislocation defect
Frenkel defect is a dislocation defect
C.
Frenkel defect is a dislocation defect
In Frenkel defect, ions in solid dislocate from their position. Hence, Frenkel defect is a dislocation defect.
The vacant space in bcc lattice cell is
26%
48%
23%
23%
D.
23%
Packing efficiency in bcc lattice = 68%
Vacant space in bcc lattice = 100-68 = 32%
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