chemistry · xenon hexafluoride reacts with silica to form a xenon compound the oxidation state of...
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Chemistry
Single correct answer type:
1. Which one of the following species is paramagnetic in nature?
(A)
(B)
(C)
(D)
Solution: (D)
The number of unpaired electrons and electronic configuration of the given species is
shown below
( ) [ ] [ ]
No. of unpaired electron
( ) [ ] [ ]
No. of unpaired electron
( ) [ ] [ ]
No. of unpaired electron
( ) [ ] [ ]
Number of unpaired electrons
The correct option among the following is ( )
2. Given that, for the reaction,
( ) ⁄
( ) ⁄
( ) ⁄
The bond dissociation energy of is
(A) ⁄
(B) ⁄
(C) ⁄
(D) ⁄
Solution: (C)
Given,
⁄
In this reaction, one mole of is formed
of the reaction will remain same,
i.e., ⁄
Let the bond dissociation energy of bond be
For the given reaction,
( ) ( )
( )
( )
⁄
3. The pair of structures given below represents
(A) Chain isomers
(B) Position isomers
(C) Tautomers
(D) Metamers
Solution: (B)
The pair of the given
represents position isomers. In case of position isomers, the difference lies in the
position of substituent groups or atom in the same chain.
4. In the extraction of copper from its sulphide ore, the metal is formed by the reduction
of with
(A)
(B)
(C)
(D)
Solution: (C)
In the extraction of copper from its sulphide ore, the metal is formed by the reduction of
with This reaction completes with the process of auto-reduction. Chemical
reaction occurring in this reaction is as follows
The molten copper is allowed to cool. During cooling, dissolved comes out in the
form of blisters, so it is called blister copper.
5. For the following reaction,
( ) ( ) ( ) ( ) at
Then, for this equilibrium is
(A)
(B)
(C)
(D)
Solution: (B)
Given,
For equilibrium, the Gibb’s free energy is calculated by using the formula.
or,
6. Xenon hexafluoride reacts with silica to form a xenon compound The oxidation
state of xenon in is
(A)
(B)
(C)
(D)
Solution: (C)
Xenon hexa fluoride reacts with silica to form as
The oxidation state of xenon in is as calculated below:
Let the oxidation state of is
( ) ( )
7. Neopentyl chloride reacts with benzene in presence of a Lewis acid ( ) to form
(A)
(B)
(C)
(D)
Solution: (B)
8. Lead is extracted from galena ( ) either by following ways.
( ) →
→
( ) →
→
Auto-reduction process is
(A) →
→
(B) →
→
(C) Both →
→
and →
→
(D) None of these
Solution: (B)
In auto-reduction, no external reducing agent is required. In such reduction reaction, the
product formed acts as a reducing agent and reduces the oxide to metal. Thus, only
reaction is called auto-reduction.
→
( ct as a reducing agent)
9. In the reaction,
The major product formed is
(A)
(B)
(C)
(D)
Solution: (C)
The given reaction is an example of Perkin condensation. In this, reaction aromatic
aldehydes react with acid anhydride of an aliphatic acid in presence of sodium salt of
same acid to form unsaturated acid. The steps involved in the process are as
follows
Thus, the correct option is (C).
10. Which one of the following represents the correct structure of cellulose?
(A) Branched, ( ) and ( ) glucose
(B) Unbranched, ( ) glucose
(C) Branched, ( ) glucose
(D) Unbranched, ( ) glucose
Solution: (D)
Cellulose has a straight chain polysaccharide composed only of The
glucose glucose. These glucose units are linked together by
glycosidic linkage. The structure is shown below:
Structure of cellulose
11. The correct formula for plaster of Paris is
(A)
(B)
(C)
(D)
Solution: (C)
Plaster of Paris (POP) is a hemihydrate of calcium sulphate. Its chemical formula is
[ ( ) ]
12. The value of for the reaction,
is At a given time, the composition of reaction mixture is
[ ] [ ] [ ] In which direction, the reaction will proceed?
(A) Forward direction
(B) Reverse direction
(C) No net reaction occur
(D) None of these
Solution: (B)
For the reaction, the reaction quotient is given by
[ ][ ] [ ] ⁄
Given that,
[ ] [ ] [ ]
Then, ( )( )
( )
As, so the reaction will proceed in the reverse direction.
13. Which of the following chemicals are used to manufacture methyl isocyanate that
caused "Bhopal tragedy"?
( ) Methylamine
( ) Phosgene
( ) Phosphine
( ) Dimethylamine
(A) ( ) and ( )
(B) ( ) and ( )
(C) ( ) and ( )
(D) ( ) and ( )
Solution: (A)
Methyl isocyanate ( ) is industrially prepared by the reaction of methyl amine
and phosgene (carbonyl chloride).
14. The correct order of ease of adsorption of the hydrated alkali metal ions on an ion
exchange resin is
(A)
(B)
(C)
(D)
Solution: (A)
Ease of adsorption of the hydrated alkali metal ions on an ion exchange resin
decreases as the size of the alkali metal ion increases. Since. the order of the size of
the alkali metal ions is
Thus, the ease of adsorption follows the order
15. Identify the major product that is obtained on treatment of ( ) with
⁄ is
(A) ( )
(B)
(C)
(D)
Solution: (B)
ccording to Saytzeff’s rule, dehydrohalogenation occur in such a way that the major
product is more highly substituted product.
( )
→
( ajor)
( inor)
16. Among the following, the non-aromatic heterocyclic compound is
(A) Piperidine
(B) Pyrrole
(C) Furan
(D) Pyridine
Solution: (A)
Pyridine is aromatic, since, it satisfies all the conditions of a compound to be aromatic
(here, lone pair on atom is and used in delocalization).
Pyrrole is also aromatic and here, lone pair on atom is used in delocalization.
Furan also follows Huckels rule and other conditions for a compound to be aromatic.
Piperidine is non-aromatic because, in it rule is not followed and moreover, no
delocalization of electron takes place.
17. If ion is larger than ions and ion is larger than ion, which of the
following will be stable salt in water?
(A) Sodium chloride
(B) Sodium sulphide
(C) Magnesium sulphide
(D) Magnesium chloride
Solution: (C)
Higher the lattice energy, lower the solubility and more stable the salt in water. Since,
lattice energy varies directly with charge. Therefore, among the four combinations
given, the lattice energy of is higher than those of and . Hence,
is stable salt in water and least soluble salt.
18.
Product P is
(A)
(B)
(C)
(D)
Solution: (B)
19. Which of the following is correct statement?
(A) Aluminum dissolves in dilute mineral acids but is made passive by concentrated
nitric acid.
(B) Aluminum vessel can be used as storage of
(C) Aluminum chloride does not dissociate in water.
(D) is soluble in anhydrous .
Solution: (A)
( ) Aluminum is made passive by due to formation of oxide layer. Hence,
does not react further but other acids react.
( )
( ) reacts with as
Thus, cannot be stored in a vessel made of
( ) Aluminum chloride dissociate in water.
( ) is insoluble in anhydrous
Thus, the only correct statement among the given options is ( ).
20. If molar conductivity of and ions are and respectively,
then the molar conductivity of at infinite dilution is
(A)
(B)
(C)
(D)
Solution: (D)
Given,
As we know that,
21. An atom forms face centred cubic crystal with density ⁄ and edge
length The molecular mass of atom is is
(A)
(B)
(C)
(D)
Solution: (B)
Given,
Density ( ) ⁄
Edge length ( )
( )
The molecular mass of atom in a lattice can be calculated by using the formula
( ) ( )
22. In a crystalline solid, having formula , oxide ions are arranged in cubic close
packed lattice while, cations are present is tetrahedral voids and cations are present
in octahedral voids. The percentage of tetrahedral voids occupied by is
(A)
(B)
(C)
(D)
Solution: (A)
In a cubic close packed lattice of oxide ions, there would be two tetrahedral and one
octahedral void per oxide ion.
Since, the formula shows the presence of oxide ions, the number of tetrahedral voids
is eight and that of octahedral voids is four. Out of the eight tetrahedral voids, one is
occupied by .
Percentage of tetrahedral voids occupied
23. Conversion of oxygen into ozone is non-spontaneous at
(A) Low temperature
(B) All temperature
(C) High temperature
(D) Room temperature
Solution: (C)
Ozone is not stable at high temperature.
So, it decomposes into oxygen at high temperature.
Thus, the reverse of this reaction is non-spontaneous at high temperature.
24. A flask contained at , and a flask contained at
. The two flask were then connected so that each gas filled their combined
volume. Assume, no change in temperature, total pressure is
(A)
(B)
(C)
(D)
Solution: (D)
Given,
Total number of moles
Total volume
Total pressure ( )
25. For the dot structure shown, the most likely elements and are
(A) Carbon, fluorine
(B) Carbon, hydrogen
(C) Carbon, oxygen
(D) Oxygen, carbon
Solution: (A)
is tetravalent without lone pair. has three lone pair and one bond pair. Thus, is
carbon and is halogen or, carbon, fluorine
26. Valence electrons in the element are and that in element is . Most probable
compound formed from and is
(A)
(B)
(C)
(D)
Solution: (D)
Valence electrons in
Valence electrons in
Thus, is electropositive and is electronegative, can lose three electrons and can
gain two electrons to attain stable configuration. Hence, exists as and as
and compound is
27. A compound, containing only carbon, hydrogen and oxygen has a molecular weight
of . On complete oxidation, it is converted into a compound of molecular weight is .
The original compound is
(A) Alcohol
(B) Acid
(C) Aldehyde
(D) Ether
Solution: (C)
On complete oxidation, the obtained compound shows increment in molecular weight of
only 16. It means only one oxygen atom is added here. This condition is fulfilled by only
aldehyde which on oxidation gives acid.
[ ]→
Hence, original compound must be an aldehyde. The aldehyde with molecular weight
is acetaldehyde.
olecular
weight 44
[ ] →
olecularweight 6
28. Number of photons emitted by a ( ) yellow lamp in is ( of yellow
light is )
(A)
(B)
(C)
(D)
Solution: (C)
As we know that,
…(i)
( )
Putting the value in Equation (i) we get
29. In Kjeldahl's method, the nitrogen present in an organic compound is quantitatively
converted into
(A) Gaseous ammonia
(B) Ammonium sulphate
(C) Ammonium phosphate
(D) Ammonia
Solution: (D)
In Kjeldahl’s method, the nitrogen is quantitatively converted into ammonia by heating
with
From organic
ompound
→ ( )
( )
30. In the reversible reaction,
the rate of disappearance of is equal to
(A)
[ ]
(B) [ ] [ ]
(C) [ ] [ ]
(D) ( )[ ]
Solution: (B)
Rate of reaction
[ ]
[ ] [ ]
Rate of disappearance of
i.e. [ ]
[ ]
[ ]
31. If ( ) and ( ) then the of the cell
| ( )|| ( )| is
(A) Equal to
(B) Less than
(C) Greater than
(D) Equal to
Solution: (C)
The cell reaction is
From Nernst equation
( )
32. For the electrochemical cell, | || || | the overall cell reaction is
(A) ( )
(B)
(C) ( )
(D) ( )
Solution: (C)
For the electrochemical cell,
| || || |
The cell reaction is
33. Which one of the following electrolytes has the same value of van’t Hoff factor ( ) as
that of [ ( ) ]
(A) ( )
(B)
(C) [ ( ) ]
(D) ( )
Solution: (A)
The value of van’t Hoff factor of the given molecule is as follows:
( )
[ ( ) ] [ ( ) ]
( )
The van’t Hoff factor for [ ( ) ] is
[ ( ) ] [ ( ) ]
( ) has the same value of van’t Hoff factor as that of [ ( ) ]
34. The van’t Hoff factor for ( ) solution is The degree of dissociation
is
(A)
(B)
(C)
(D)
Solution: (B)
Total number of moles
Then, van’t Hoff factor,
or,
or,
% dissociation
35. The IUPAC name of the following compound is
(A) propylpent ene
(B) ethylpent ene
(C) ethylhex ene
(D) ethylhex ene
Solution: (D)
Select the longest possible carbon atom chain, number the chain and write the name of
compound according to IUPAC rules. Thus, the correct IUPAC name of the compound
given is
36. Bleeding due to a cut can be stopped by applying ferric chloride solution in the
laboratory. This is due to
(A) Coagulation of negatively charged blood particles by ions.
(B) Coagulation of positively charged blood particles by ions.
(C) Reaction taking place between ferric ions and the hemoglobin forming a complex.
(D) Common element, iron, in both and hemoglobin.
Solution: (A)
Bleeding due to a cut can be stopped by applying or alum solution. This is due to
coagulation of negatively charged colloidal blood particles (albuminoid substance) by
positively charged ions. These substances are used as styptic (which check the
flow of blood).
37. Relative stabilities of the following carbocations will be in the order
(A)
(B)
(C)
(D)
Solution: (A)
The dispersal of the charge stabilises the carbocation. More the number of alkyl groups;
the greater is the dispersal of positive charge and therefore more is the stability of
carbocation. Thus, the correct order is
38. Among the following species, the one which become paramagnetic on heating at
is
(A)
(B)
(C)
(D) Both and
Solution: (D)
All magnetically ordered solids, i.e. ferromagnetic; antiferromagnetic; ferrimagnetic
changes to paramagnetic state at high temperature because of the randomisation of
spins.
Ferrimagnetic species, such as (magnetite) and ferrites, i.e. and
loses ferrimagnetism on heating and transforms to paramagnetism.
39. Which of the following is not a surfactant?
(A) ( ) ( )
(B) ( )
(C) ( )
(D) ( )
Solution: (B)
Every surfactant contains two parts a hydrophobic part and a hydrophilic part. The
compound ( ) contains only hydrophobic part but no hydrophilic part,
hence, it is not a surfactant.
All other options are surfactant
( ) ( )
( )
( )
40. In the complex [ ( ) ] the oxidation number of is
(A)
(B)
(C)
(D)
Solution: (B)
Let the oxidation number of is in the complex [ ( ) ]
( ) ( )
Thus, the oxidation number of is
41. Arrange the following polymers in increasing order of their intermolecular forces.
Nylon buna polythene, neoprene
(A) Neoprene buna nylon polythene
(B) Neoprene buna polythene nylon
(C) Polythene nylon buna neoprene
(D) Polythene buna nylon neoprene
Solution: (B)
The increasing order of intermolecular forces in different polymers is elastomers
plastics fibres. So, in order to solve such problem, first classify the given polymer into
the above classes and then arrange them in increasing order of forces. Neoprene
(synthetic rubber) is an elastomer, buna is also an elastomer, polythene is plastic
and nylon is a fibre. So, the increasing order of intermolecular forces of the given
polymer is
Neoprene buna polythene nylon
42. The product of electrolysis of aqueous solution on anode and cathode
respectively is
(A) and
(B) and
(C) and
(D) and
Solution: (A)
In case of electrolysis of aqueous oxidation and reduction reaction occurs at
anode and cathode respectively as shown below:
<b>At cathode</b>
( )
( )
( )
<b>At anode</b>
( )
( )
Net cell reaction is as follows
( ) ( ) ( ) ( )
( )
( )
Thus, the product of electrolysis of solution on cathode and anode is and
43. In adiabatic conditions, mole of gas at is expanded such that its volume
becomes times. Then, the work done is ( )
(A)
(B)
(C)
(D)
Solution: (D)
Given,
In adiabatic conditions
( )
or,
(
)
(
)
(
)
Or,
Thus, hence, cooling takes place due to expansion under adiabatic condition.
( for adiabatic change)
because gas expands.
Then, ( )
( )
44. The compounds and are distinguished by
(A) and in
(B) in
(C) Dilute
(D) and naphthol
Solution: (D)
45. Alkali metals readily dissolve in liquid ammonia to give blue coloured solutions. The
blue colour is believed to be due to
(A) Ammoniated cations
(B) Ammoniated anions
(C) Ammoniated electrons
(D) Ammoniated cations and ammoniated electrons
Solution: (C)
Alkali metals readily dissolve in liquid ammonia. It gives blue coloured solution due to
ammoniated electrons.
The reaction is shown below:
( ) ( ) ( )
( ) lue colour
46. ⁄→
( )
( ) ⁄→
What is the product is the above reaction?
(A) Methyl ethanoate
(B) Ethanoic acid
(C) Propanal
(D) Methyl propanoate
Solution: (A)
The reaction is as follows
Hence, the product is methyl ethanoate.
47. If osmotic pressure of ( ⁄ ) solution of sucrose is same as ( ⁄ ) solution
of then the molecular mass of ( ⁄ ) is
(A)
(B)
(C)
(D) None of these
Solution: (A)
solution of sucrose ( ⁄ ) means of sucrose is dissolved in of solution.
Similarly, ( ⁄ ) solution of means of present in of solution.
As we know that, osmotic pressure ( ) or
where number of moles
of solute.
Since, (for sucrose solution)
(for solution)
[
]
Molecular weight
Molecular weight
48. Which of the following is disproportionation reaction?
(A)
(B)
(C)
(D)
Solution: (D)
Reactions in which the same substance is oxidized as well as reduced are called
disproportionation reaction. Writing the oxidation number of each element above its
symbol in the given reactions.
Thus, in the reaction of and is both oxidized as well as reduced. Hence, the
oxidation number increases from in to in and decreases from in
to in
49. Among the following, the suitable reagent for Wurtz reaction is
(A) ⁄
(B) ⁄
(C) ⁄
(D) ⁄
Solution: (B)
The suitable reagent for Wurtz reaction is ⁄ An ethereal solution of an alkyl
halide is treated with sodium to produce higher alkanes. This reaction involves the
function of new
bond. e.g.
thyl bromide
→
ropane
50. Which type of drugs come under anti-microbial drugs?
(A) Antiseptics, antacids, antihista mines
(B) Tranquilizers, antiseptics, antifertility
(C) Tranquilizers, analgesics, antiseptics
(D) Antiseptics, antibiotics, disinfectants
Solution: (D)
Bacteria, virus, fungi and other pathogens are microorganisms. These may cause
diseases in human beings and animals. An antimicrobial drug prevents the development
or inhibit the pathogenic action of microorganisms such as bacteria (antibacterial drug),
virus (antiviral drugs), fungi (antifungal drugs) or other parasite (antiparasite drugs
selectively). Antibiotics, antiseptics and disinfectants are antimicrobial drugs.
51. Which of the following pair behaves as strong and weak base hydride respectively
(A)
(B)
(C)
(D)
Solution: (B)
The basic strength of given hydrides decreases in the order as follows
This is due to the decrease in the availability of the lone pair of electrons which depends
on the size of central atom that increase from to . Therefore, and acts as
a strong and weak base hydride respectively.
52. mong the following, the correct formula of arshall’s acid is
(A)
(B)
(C)
(D)
Solution: (B)
The correct formula of arshall’s acid is It is known as peroxodisulphuric acid
having Sulphur (S) in oxidation state. The structure of this acid is shown below:
53. When hydrogen peroxide is added to acidified solution of dichromate a deep
blue coloured complex of chromic peroxide is formed. Oxidation state of in
is
(A)
(B)
(C)
(D)
Solution: (C)
When is added to an acidified solution of dichromate a deep blue complex
chromic peroxide, is formed.
( )
This deep blue coloured complex has the following structure
Let the oxidation state of be
In ( )
( ) ( )
54. When phenol is treated with and followed by acidification,
salicylaldehyde is obtained. Which of the following species is involved in the above
mentioned reaction as intermediates?
(A)
(B)
(C)
(D)
Solution: (A)
On refluxing alkaline solution of phenol with at and on subsequent
acidification, hydroxy benzaldehyde (salicylaldehyde) is obtained. This reaction is
known as Riemer Tiemann reaction.
<b>Mechanism</b>
correct option is ( )
55. Which of the following is the correct sequence of step involved in the mechanism of
Cannizzaro reaction?
(A) Nucleophilic attack, transfer of and transfer of
(B) Transfer of transfer of and nucleophilic attack
(C) Transfer of nucleophilic attack and transfer of
(D) Electrophilic attack by transfer of and transfer of
Solution: (A)
Cannizzaro reaction involves the aldehydes which do not have an hydrogen atom,
undergo self oxidation and reduction reaction on heating with conc. alkali.
→
<b>Mechanism</b>
<b>Step I:</b> Attack of nucleophile to the carbonyl carbon.
<b>Step II:</b> Transfer of hydride ion from anion I to second molecule of aldehyde
and finally rapid transfer of proton takes place.
56.
What is the product is the above reaction?
(A)
(B)
(C)
(D)
Solution: (D)
In the first step, hydroxyl group of carboxylic acid is replaced by chlorine atom on
treating with which on further reaction with produced an amide. The amide
undergoes Hoff mann bromamide reaction to produce an amine.
57. Red blood cells are placed in a solution and neither haemolysis nor crenation
occurs. Therefore, the solution is
(A) Hypertonic
(B) Hypotonic
(C) Isotonic
(D) Isotopic
Solution: (C)
When red blood cells are placed in a solution and neither hemolysis nor crenation
occurs. This means that solution is isotonic in nature, since in isotonic solution, there is
no process of osmosis takes place.
58. If is element of actinoids series, the degree of complex formation decreases in
the order
(A)
(B)
(C)
(D)
Solution: (B)
The higher the charge on the metal ion, smaller is the ionic size and more is the
complex forming ability. Thus, the degree of complex formation decreases in the order
The higher tendency of complex formation of as compared to is due to high
concentration of charge on metal atom
59. A chemical reaction was carried out at and The rate constant were
found to be and respectively, then
(A)
(B)
(C)
(D)
Solution: (B)
For every rise, rate constant gets doubled. Hence, for every rise, rate
constant will be times.
Therefore, according to the given statement,
60. Which of the following compound can exhibit tautomerism?
(A)
(B)
(C)
(D)
Solution: (B)
Presence of atom along with a multibonded functional group is an essential
condition for exhibiting tautomerism.
Satisfies this condition, therefore exhibit tautomerism.