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NEET 2018 CODE-AA

2018 · 54 questions · First 10 Solutions Free
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Q46 mcq
The correct order of N-compounds in decreasing order of oxidation states is
a.
HNO3, NH4Cl, NO, N2
b.
HNO3, NO, NH4Cl, N2
c.
HNO3, NO, N2, NH4Cl Correct Answer
d.
NH4Cl, N2, NO, HNO3
Step-by-Step AI Explanation
Verified Method
Oxidation states of nitrogen are: HNO3 = +5, NO = +2, N2 = 0, NH4Cl = -3. Hence decreasing order is HNO3 > NO > N2 > NH4Cl.
Q46 mcq
The correct order of N-compounds in decreasing order of oxidation states is
a.
HNO3, NH4Cl, NO, N2
b.
HNO3, NO, NH4Cl, N2
c.
HNO3, NO, N2, NH4Cl Correct Answer
d.
NH4Cl, N2, NO, HNO3
Step-by-Step AI Explanation
Verified Method
Oxidation states of N are: HNO3 = +5, NO = +2, N2 = 0, NH4Cl = -3. Hence decreasing order is HNO3 > NO > N2 > NH4Cl.
Q47 mcq
Which one of the following elements is unable to form MF6^3− ion?
a.
B Correct Answer
b.
Al
c.
Ga
d.
In
Step-by-Step AI Explanation
Verified Method
Boron has no vacant d-orbitals in its valence shell and cannot expand its coordination number beyond 4, so it cannot form BF6^3−.
Q47 mcq
Which one of the following elements is unable to form MF6^3- ion?
a.
B Correct Answer
b.
Al
c.
Ga
d.
In
Step-by-Step AI Explanation
Verified Method
Boron has no vacant d-orbitals and cannot expand its covalency to form hexafluoro complex BF6^3-. Hence B cannot form MF6^3-.
Q48 mcq
Considering Ellingham diagram, which of the following metals can be used to reduce alumina?
a.
Mg Correct Answer
b.
Zn
c.
Fe
d.
Cu
Step-by-Step AI Explanation
Verified Method
A metal more reactive than aluminium can reduce alumina. Among the given options, Mg is the strongest reducing metal.
Q49 mcq
The correct order of atomic radii in group 13 elements is
a.
B < Ga < Al < Tl < In
b.
B < Al < Ga < In < Tl
c.
B < Al < In < Ga < Tl
d.
B < Ga < Al < In < Tl Correct Answer
Step-by-Step AI Explanation
Verified Method
Due to poor shielding by d- and f-electrons, the size trend is irregular, but the accepted order is B < Ga < Al < In < Tl.
Q50 mcq
Which of the following statements is not true for halogens?
a.
All but fluorine show positive oxidation states Correct Answer
b.
All are oxidizing agents
c.
All form monobasic oxyacids
d.
Chlorine has the highest electron-gain enthalpy
Step-by-Step AI Explanation
Verified Method
Fluorine does not show positive oxidation states; in HOF it has oxidation state +1 for oxygen’s sake? Actually the standard NCERT point is that fluorine shows only -1 oxidation state in its compounds and no positive oxidation state. Hence statement (a) is not true as written.
Q51 mcq
In the structure of ClF3, the number of lone pairs of electrons on the central atom Cl is
a.
Four
b.
Two Correct Answer
c.
One
d.
Three
Step-by-Step AI Explanation
Verified Method
ClF3 has 5 electron pairs around chlorine: 3 bond pairs and 2 lone pairs, giving a T-shaped molecule.
Q52 mcq
Identify the major products P, Q and R in the following sequence of reactions: benzene reacts with propyl chloride in presence of anhydrous AlCl3, then (i) O2, (ii) H3O+/Δ.
a.
CH3CH(OH)CH3, ...
b.
CH3CH2CHO, CH3COOH, ...
c.
CH3CH2CHO, CH3CH2OH, ...
d.
(CH3)2CHOH, CH3COCH3, ... Correct Answer
Step-by-Step AI Explanation
Verified Method
Propyl chloride with AlCl3 undergoes rearrangement to give isopropylbenzene type intermediate; oxidation followed by acidic hydrolysis of the hydroperoxide gives phenol/acetone-type products as indicated. The correct option given is (4), matching the rearrangement products shown in the source.
Q53 mcq
Which of the following compounds can form a zwitterion?
a.
Benzoic acid
b.
Acetanilide
c.
Aniline
d.
Glycine Correct Answer
Step-by-Step AI Explanation
Verified Method
Glycine contains both acidic -COOH and basic -NH2 groups and exists as a zwitterion in solution.
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Q54 mcq
Regarding cross-linked or network polymers, which of the following statements is incorrect?
a.
Examples are bakelite and melamine.
b.
They are formed from bi- and tri-functional monomers.
c.
They contain covalent bonds between various linear polymer chains.
d.
They contain strong covalent bonds in their polymer chains.
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Q55 mcq
Nitration of aniline in strong acidic medium also gives m-nitroaniline because
a.
In absence of substituents nitro group always goes to m-position.
b.
In electrophilic substitution reactions amino group is meta directive.
c.
Inspite of substituents nitro group always goes to only m-position.
d.
In acidic (strong) medium aniline is present as anilinium ion.
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Q56 mcq
The difference between amylose and amylopectin is
a.
Amylopectin has 1→4 α-linkage and 1→6 β-linkage
b.
Amylose has 1→4 α-linkage and 1→6 β-linkage
c.
Amylopectin has 1→4 α-linkage and 1→6 α-linkage
d.
Amylose is made up of glucose and galactose
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Q56 mcq
The difference between amylose and amylopectin is
a.
Amylopectin have 1 → 4 α-linkage and 1 → 6 β-linkage
b.
Amylose have 1 → 4 α-linkage and 1 → 6 β-linkage
c.
Amylopectin have 1 → 4 α-linkage and 1 → 6 α-linkage
d.
Amylose is made up of glucose and galactose
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Q57 mcq
A mixture of 2.3 g formic acid and 4.5 g oxalic acid is treated with concentrated H2SO4. The evolved gaseous mixture is passed through KOH pellets. Weight (in g) of the remaining product at STP will be
a.
2.8
b.
3.0
c.
1.4
d.
4.4
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Q58 mcq
Which of the following oxides is most acidic in nature?
a.
BaO
b.
BeO
c.
MgO
d.
CaO
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Q59 mcq
Which oxide of nitrogen is not a common pollutant introduced into the atmosphere both due to natural and human activity?
a.
N2O
b.
NO2
c.
N2O5
d.
NO
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Q60 mcq
The compound A on treatment with Na gives B, and with PCl5 gives C. B and C react together to give diethyl ether. A, B and C are in the order
a.
C2H5Cl, C2H6, C2H5OH
b.
C2H5OH, C2H5Cl, C2H5ONa
c.
C2H5OH, C2H6, C2H5Cl
d.
C2H5OH, C2H5ONa, C2H5Cl
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Q61 mcq
The compound C7H8 undergoes the following reactions: C7H8 —(Cl2/Br2/Fe, Δ)→ A —(Zn/HCl)→ B —(Fe)→ C. The product C is
a.
3-bromo-2,4,6-trichlorotoluene
b.
o-bromotoluene
c.
m-bromotoluene
d.
p-bromotoluene
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Q62 mcq
Hydrocarbon (A) reacts with bromine by substitution to form an alkyl bromide which by Wurtz reaction is converted to a gaseous hydrocarbon containing less than four carbon atoms. (A) is
a.
CH3–CH3
b.
CH2=CH2
c.
CH≡CH
d.
CH4
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Q63 mcq
Which of the following molecules represents the order of hybridisation sp2, sp2, sp, sp from left to right atoms?
a.
CH2=CH–CH=CH2
b.
CH2=CH–C≡CH
c.
HC≡C–C≡CH
d.
CH3–CH=CH–CH3
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Q65 mcq
Which of the following is correct with respect to –I effect of the substituents? (R = alkyl)
a.
–NH2 > –OR > –F
b.
–NR2 < –OR < –F
c.
–NH2 < –OR < –F
d.
–NR2 > –OR > –F
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Q65 mcq
Which of the following is correct with respect to the −I effect of the substituents? (R = alkyl)
a.
−NH2 > −OR > −F
b.
−NR2 < −OR < −F
c.
−NH2 < −OR < −F
d.
−NR2 > −OR > −F
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Q66 mcq
In the reaction of phenol with chloroform and aqueous NaOH, the electrophile involved is
a.
Dichloromethyl anion (CHCl2–)
b.
Formyl cation (CHO+)
c.
Dichloromethyl cation (CHCl2+)
d.
Dichlorocarbene (:CCl2)
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Q66 mcq
In the reaction of phenol with CHCl3 and NaOH, the electrophile involved is
a.
Dichloromethyl anion, CHCl2−
b.
Formyl cation, CHO+
c.
Dichloromethyl cation, CHCl2+
d.
Dichlorocarbene, :CCl2
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Q67 mcq
Carboxylic acids have higher boiling points than aldehydes, ketones and even alcohols of comparable molecular mass. It is due to their
a.
More extensive association of carboxylic acid via van der Waals force of attraction
b.
Formation of carboxylate ion
c.
Formation of intramolecular H-bonding
d.
Formation of intermolecular H-bonding
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Q68 mcq
Compound A, C8H10O, is found to react with NaOI (produced by reacting Y with NaOH) and yields a yellow precipitate with characteristic smell. A and Y are respectively
a.
C6H5CH(OH)CH3 and I2
b.
CH3CH2CH(OH)CH3 and I2
c.
C2H5OH and I2
d.
C6H5OH and I2
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Q69 mcq
Match the metal ions given in Column I with the spin magnetic moments of the ions given in Column II and assign the correct code: Column I a. Co3+ b. Cr3+ c. Fe3+ d. Ni2+ Column II i. 8 BM ii. 35 BM iii. 3 BM iv. 24 BM v. 15 BM
a.
iv i ii iii
b.
i ii iii iv
c.
iv v ii i
d.
iii v i ii
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Q70 mcq
Which one of the following ions exhibits d-d transition and paramagnetism as well?
a.
MnO4−
b.
Cr2O7^2−
c.
CrO4^2−
d.
MnO4^2−
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Q71 mcq
Iron carbonyl, Fe(CO)5 is
a.
Trinuclear
b.
Mononuclear
c.
Tetranuclear
d.
Dinuclear
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Q72 mcq
The type of isomerism shown by the complex [CoCl2(en)2] is
a.
Ionization isomerism
b.
Coordination isomerism
c.
Geometrical isomerism
d.
Linkage isomerism
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Q73 mcq
The geometry and magnetic behaviour of the complex [Ni(CO)4] are
a.
Square planar geometry and paramagnetic
b.
Tetrahedral geometry and diamagnetic
c.
Square planar geometry and diamagnetic
d.
Tetrahedral geometry and paramagnetic
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Q73 mcq
The geometry and magnetic behaviour of the complex [Ni(CO)4] are:
a.
Square planar geometry and paramagnetic
b.
Tetrahedral geometry and diamagnetic
c.
Square planar geometry and diamagnetic
d.
Tetrahedral geometry and paramagnetic
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Q74 mcq
Following solutions were prepared by mixing different volumes of NaOH and HCl of different concentrations: a. 60 mL M/10 HCl + 40 mL M/10 NaOH b. 55 mL M/10 HCl + 45 mL M/10 NaOH c. 75 mL M/5 HCl + 25 mL M/5 NaOH d. 100 mL M/10 HCl + 100 mL M/10 NaOH pH of which one of them will be equal to 1?
a.
d
b.
a
c.
b
d.
c
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Q74 mcq
Following solutions were prepared by mixing different volumes of NaOH and HCl of different concentrations: a. 60 mL 10 M HCl + 40 mL 10 M NaOH b. 55 mL 10 M HCl + 45 mL 10 M NaOH c. 75 mL 5 M HCl + 25 mL 5 M NaOH d. 100 mL 10 M HCl + 100 mL 10 M NaOH pH of which one of them will be equal to 1?
a.
d
b.
a
c.
b
d.
c
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Q75 mcq
On which of the following properties does the coagulating power of an ion depend?
a.
Both magnitude and sign of the charge on the ion
b.
Size of the ion alone
c.
The magnitude of the charge on the ion alone
d.
The sign of charge on the ion alone
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Q76 mcq
Given van der Waals constant for NH3, H2, O2 and CO2 are respectively 4.17, 0.244, 1.36 and 3.59, which one of the following gases is most easily liquefied?
a.
O2
b.
H2
c.
NH3
d.
CO2
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Q77 mcq
The solubility of BaSO4 in water is 2.42 × 10^-3 g L^-1 at 298 K. The value of its solubility product (Ksp) will be (Given molar mass of BaSO4 = 233 g mol^-1)
a.
1.08 × 10^-14 mol^2 L^-2
b.
1.08 × 10^-12 mol^2 L^-2
c.
1.08 × 10^-10 mol^2 L^-2
d.
1.08 × 10^-8 mol^2 L^-2
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Q78 mcq
In which case is number of molecules of water maximum?
a.
0.00224 L of water vapours at 1 atm and 273 K
b.
0.18 g of water
c.
18 mL of water
d.
10^-3 mol of water
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Q79 mcq
The correct difference between first and second order reactions is that
a.
A first-order reaction can be catalyzed; a second-order reaction cannot be catalyzed
b.
The half-life of a first-order reaction does not depend on [A]0; the half-life of a second-order reaction does depend on [A]0
c.
The rate of a first-order reaction does not depend on reactant concentrations; the rate of a second-order reaction does depend on reactant concentrations
d.
The rate of a first-order reaction does depend on reactant concentrations; the rate of a second-order reaction does not depend on reactant concentrations
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Q80 mcq
Among CaH2, BeH2 and BaH2, the order of ionic character is
a.
BeH2 < BaH2 < CaH2
b.
CaH2 < BeH2 < BaH2
c.
BeH2 < CaH2 < BaH2
d.
BaH2 < BeH2 < CaH2
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Q80 mcq
Among CaH2, BeH2, BaH2, the order of ionic character is
a.
BeH2 < BaH2 < CaH2
b.
CaH2 < BeH2 < BaH2
c.
BeH2 < CaH2 < BaH2
d.
BaH2 < BeH2 < CaH2
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Q81 mcq
Consider the change in oxidation state of bromine corresponding to different emf values as shown below: BrO4− / BrO3− / HBrO / Br2 / Br−. The species undergoing disproportionation is
a.
Br2
b.
BrO4−
c.
BrO3−
d.
HBrO
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Q81 mcq
Consider the change in oxidation state of bromine corresponding to different emf values as shown below: BrO4−/BrO3− : 1.82 V BrO3−/HBrO : 1.5 V HBrO/Br2 : 1.595 V Br2/Br− : 1.0652 V Then the species undergoing disproportionation is
a.
Br2
b.
BrO4−
c.
BrO3−
d.
HBrO
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Q82 mcq
For the redox reaction MnO4− + C2O4^2− + H+ → Mn2+ + CO2 + H2O, the correct coefficients of the reactants for the balanced equation are
a.
2, 16, 5
b.
2, 5, 16
c.
16, 5, 2
d.
5, 16, 2
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Q83 mcq
Which one of the following conditions will favour maximum formation of the product in the reaction A(g) + B(g) ⇌ X(g), ΔH = −x kJ?
a.
High temperature and high pressure
b.
Low temperature and low pressure
d.
High temperature and low pressure
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Q84 mcq
When initial concentration of the reactant is doubled, the half-life period of a zero order reaction
a.
Is tripled
b.
Is doubled
c.
Is halved
d.
Remains unchanged
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Q85 mcq
The bond dissociation energies of X2, Y2 and XY are in the ratio 1 : 0.5 : 1. If ΔH for the formation of XY is −200 kJ mol−1, the bond dissociation energy of X2 will be
a.
800 kJ mol−1
b.
100 kJ mol−1
c.
200 kJ mol−1
d.
400 kJ mol−1
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Q86 mcq
The correction factor 'a' to the ideal gas equation corresponds to
a.
Electric field present between the gas molecules
b.
Volume of the gas molecules
c.
Density of the gas molecules
d.
Forces of attraction between the gas molecules
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Q87 mcq
Consider the following species: CN+, CN−, NO and CN. Which one of these will have the highest bond order?
a.
CN+
b.
CN−
c.
NO
d.
CN
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Q88 mcq
Magnesium reacts with an element (X) to form an ionic compound. If the ground state electronic configuration of X is 1s2 2s2 2p3, the simplest formula for this compound is
a.
Mg2X
b.
MgX2
c.
Mg2X3
d.
Mg3X2
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Q88 mcq
Magnesium reacts with an element X to form an ionic compound. If the ground state electronic configuration of X is 1s2 2s2 2p3, the simplest formula for this compound is
a.
Mg2X
b.
MgX2
c.
Mg2X3
d.
Mg3X2
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Q89 mcq
Iron exhibits bcc structure at room temperature. Above 900°C, it transforms to fcc structure. The ratio of density of iron at room temperature to that at 900°C, assuming molar mass and atomic radii of iron remain constant with temperature, is
a.
3/4
b.
4/3
c.
3/2
d.
1/2
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Q90 mcq
Which one is a wrong statement?
a.
The electronic configuration of N atom is 1s2 2s2 2px1 2py1 2pz1
b.
An orbital is designated by three quantum numbers while an electron in an atom is designated by four quantum numbers
c.
Total orbital angular momentum of electron in s orbital is equal to zero
d.
The value of m for dz2 is zero
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