NEET Chemistry 2020 All Questions with Answer Key

 1.      Sucrose on hydrolysis gives:


(1) α-D-Glucose + β-D-Glucose

(2) α-D-Glucose + β-D-Fructose

(3) α-D-Fructose + β-D-Fructose

(4) β-D-Glucose + α-D-Fructose


Answer (2)


2.     Elimination reaction of 2-Bromo-pentane to form pent-2-ene is:


(a) β-Elimination reaction

(b) Follows Zaitsev rule

(c) Dehydrohalogenation reaction

(d) Dehydration reaction


(1) (a), (c), (d)

(2) (b), (c), (d)

(3) (a), (b), (d)

(4) (a), (b), (c)


Answer (4)


3.     The number of Faradays(F) required to produce 20 g of calcium from molten CaCl2 (Atomic mass of Ca = 40 g mol–1) is:


(1) 2

(2) 3

(3) 4

(4) 1


Answer (4)


4.  An element has a body centered cubic (bcc) structure with a cell edge of 288 pm. The atomic radius is:


(1)

(2)

(3)

(4)


Answer (4)


5.     HCl was passed through a solution of CaCl2, MgCl2 and NaCl. Which of the following compound(s) crystallise(s)?


(1) Only NaCl

(2) Only MgCl2

(3) NaCl, MgCl2 and CaCl2

(4) Both MgCl2 and CaCl2


Answer (1)


6.  Find out the solubility of Ni(OH)2 in 0.1 M NaOH. Given that the ionic product of Ni(OH)2 is 2 × 10–15


(1) 2 × 10–8 M

(2) 1 × 10–13 M

(3) 1 × 108 M

(4) 2 × 10–13 M


Answer (4)


7.  For the reaction, 2Cl(g) → Cl2(g), the correct option is :


(1) ΔrH > 0 and ΔrS < 0

(2) ΔrH < 0 and ΔrS > 0

(3) ΔrH < 0 and ΔrS < 0

(4) ΔrH > 0 and ΔrS > 0


Answer (3)


8.  Which of the following is the correct order of increasing field strength of ligands to form coordination compounds?


(1)

(2)

(3)

(4)


Answer (4)


9.     The calculated spin only magnetic moment of Cr2+ ion is


(1) 4.90 BM

(2) 5.92 BM

(3) 2.84 BM

(4) 3.87 BM


Answer (1)


10.     Which of the following set of molecules will have zero dipole moment?


(1) Boron trifluoride, hydrogen fluoride, carbon dioxide, 1,3-dichlorobenzene

(2) Nitrogen trifluoride, beryllium difluoride, water, 1,3-dichlorobenzene

(3) Boron trifluoride, beryllium difluoride, carbon dioxide, 1,4-dichlorobenzene

(4) Ammonia, beryllium difluoride, water, 1,4-dichlorobenzene


Answer (3)


11.     The following metal ion activates many enzymes, participates in the oxidation of glucose to produce ATP and with Na, is responsible for the transmission of nerve signals.


(1) Copper

(2) Calcium

(3) Potassium

(4) Iron


Answer (3)


12.     An alkene on ozonolysis gives methanal as one of the product. Its structure is


(1)

(2)

(3)

(4)


Answer (2)


13.     The rate constant for a first order reaction is 4.606 × 10–3 s–1. The time required to reduce 2.0 g of the reactant to 0.2 g is :


(1) 200 s

(2) 500 s

(3) 1000 s

(4) 100 s


Answer (2)


14.     Reaction between acetone and methylmagnesium chloride followed by hydrolysis will give :

(1) Sec. butyl alcohol

(2) Tert. butyl alcohol

(3) Isobutyl alcohol

(4) Isopropyl alcohol


Answer (2)


15.     Which of the following is a natural polymer?


(1) poly (Butadiene-styrene)

(2) polybutadiene

(3) poly (Butadiene-acrylonitrile)

(4) cis-1,4-polyisoprene


Answer (4)


16.     Identify the correct statement from the following :


(a) CO2(g) is used as refrigerant for ice-cream and frozen food.

(b) The structure of C60 contains twelve six carbon rings and twenty five carbon rings.

(c) ZSM-5, a type of zeolite, is used to convert alcohols into gasoline.

(d) CO is colorless and odourless gas.


(1) (a) and (c) only

(2) (b) and (c) only

(3) (c) and (d) only

(4) (a), (b) and (c) only


Answer (3)


17.     The correct option for free expansion of an ideal gas under adiabatic condition is


(1) q = 0, ΔT < 0 and w > 0

(2) q < 0, ΔT = 0 and w = 0

(3) q > 0, ΔT > 0 and w > 0

(4) q = 0, ΔT = 0 and w = 0


Answer (4)


18.  Which of the following oxoacid of sulphur has – O – O – linkage?


(1) H2SO4, sulphuric acid

(2) H2S2O8, peroxodisulphuric acid

(3) H2S2O7, pyrosulphuric acid

(4) H2SO3, sulphurous acid


Answer (2)


19.     Identify compound X in the following sequence of reactions

(1)

(2)

(3)

(4)


Answer (2)

20.     The number of protons, neutrons and electrons in respectively, are


(1) 104, 71 and 71

(2) 71, 71 and 104

(3) 175, 104 and 71

(4) 71, 104 and 71 


Answer (4)


21.  Identify the incorrect statement.


(1) The transition metals and their compounds are known for their catalytic activity due to their ability to adopt multiple oxidation states and to form complexes.

(2) Interstitial compounds are those that are formed when small atoms like H, C or N are trapped inside the crystal lattices of metals.

(3) The oxidation states of chromium in and are not the same.

(4) Cr2+ (d4) is a stronger reducing agent than Fe2+ (d6) in water.


Answer (3)


22.     Which of the following is a cationic detergent?


(1) Sodium stearate

(2) Cetyltrimethyl ammonium bromide

(3) Sodium dodecylbenzene sulphonate

(4) Sodium lauryl sulphate


Answer (2)


23.     The freezing point depression constant (Kf) of benzene is 5.12 K kg mol–1. The freezing point depression for the solution of molality 0.078 m containing a non-electrolyte solute in benzene is (rounded off upto two decimal places) :


(1) 0.80 K

(2) 0.40 K

(3) 0.60 K

(4) 0.20 K


Answer (2)


24.  Identify the incorrect match.

 

Name

 

IUPAC Official Name

(a)

Unnilunium

(i)

Mendelevium

(b)

Unniltrium

(ii)

Lawrencium

(c)

Unnilhexium

(iii)

Seaborgium

(d)

Unununnium

(iv)

Darmstadtium


(1) (b), (ii)

(2) (c), (iii)

(3) (d), (iv)

(4) (a), (i)


Answer (3)


25.     The mixture which shows positive deviation from Raoult’s law is


(1) Benzene + Toluene

(2) Acetone + Chloroform

(3) Chloroethane + Bromoethane

(4) Ethanol + Acetone


Answer (4)


26.     Match the following :

 

Oxide

 

Nature

(a)

CO

(i)

Basic

(b)

BaO

(ii)

Neutral

(c)

Al2O3

(iii)

Acidic

(d)

Cl2O7

(iv)

Amphoteric


Which of the following is correct option?


 

(a)

(b)

(c)

(d)

(1)

(ii)

(i)

(iv)

(iii)

(2)

(iii)

(iv)

(i)

(ii)

(3)

(iv)

(iii)

(ii)

(i)

(4)

(i)

(ii)

(iii)

(iv)


Answer (1)


27.     Which one of the followings has maximum number of atoms ?


(1) 1 g of Mg(s) [Atomic mass of Mg = 24]

(2) 1 g of O2(g) [Atomic mass of O = 16]

(3) 1 g of Li(s) [Atomic mass of Li = 7]

(4) 1 g of Ag(s) [Atomic mass of Ag = 108]


Answer (3)


28.     Reaction between benzaldehyde and acetophenone in presence of dilute NaOH is known as


(1) Cannizzaro’s reaction

(2) Cross Cannizzaro’s reaction

(3) Cross Aldol condensation

(4) Aldol condensation


Answer (3)


29.     A tertiary butyl carbocation is more stable than a secondary butyl carbocation because of which of the following ?


(1) + R effect of – CH3 groups

(2) – R effect of – CH3 groups

(3) Hyperconjugation

(4) – I effect of – CH3 groups


Answer (3)


30.     Which of the following is not correct about carbon monoxide ?


(1) It reduces oxygen carrying ability of blood.

(2) The carboxyhaemoglobin (haemoglobin bound to CO) is less stable than oxyhaemoglobin.

(3) It is produced due to incomplete combustion.

(4) It forms carboxyhaemoglobin


Answer (2)


31.     Which of the following is a basic amino acid ?


(1) Alanine

(2) Tyrosine

(3) Lysine

(4) Serine


Answer (3)


32.  Urea reacts with water to form A which will decompose to form B. B when passed through Cu2+ (aq), deep blue colour solution C is formed. What is the formula of C from the following ?


(1) [Cu(NH3)4]2+

(2) Cu(OH)2

(3) CuCO3·Cu(OH)2

(4) CuSO4


Answer (1)


33.     A mixture of N2 and Ar gases in a cylinder contains 7 g of N2 and 8 g of Ar. If the total pressure of the mixture of the gases in the cylinder is 27 bar, the partial pressure of N2 is :

[Use atomic masses (in g mol–1) : N = 14, Ar = 40]


(1) 12 bar

(2) 15 bar

(3) 18 bar

(4) 9 bar


Answer (2)


34.     Identify the correct statement from the following :


(1) Blister copper has blistered appearance due to evolution of CO2.

(2) Vapour phase refining is carried out for Nickel by Van Arkel method.

(3) Pig iron can be moulded into a variety of shapes.

(4) Wrought iron is impure iron with 4% carbon.


Answer (3)


35.     Hydrolysis of sucrose is given by the following reaction.

If the equilibrium constant (KC) is 2 × 1013 at 300 K, the value of at the same temperature will be :


(1) 8.314 J mol–1K–1 × 300 K × ln(2 × 1013)

(2) 8.314 J mol–1K–1 × 300 K × ln(3 × 1013)

(3) –8.314 J mol–1K–1 × 300 K × ln(4 × 1013)

(4) –8.314 J mol–1K–1 × 300 K × ln(2 × 1013)


Answer (4)


36.     Identify a molecule which does not exist.


(1) Li2

(2) C2

(3) O2

(4) He2


Answer (4)


37.     An increase in the concentration of the reactants of a reaction leads to change in

(1) heat of reaction

(2) threshold energy

(3) collision frequency

(4) activation energy


Answer (1)


38.     Which of the following alkane cannot be made in good yield by Wurtz reaction?


(1) 2,3-Dimethylbutane

(2) n-Heptane

(3) n-Butane

(4) n-Hexane


Answer (2)


39.     Which of the following amine will give the carbylamine test?

(1)

(2)

(3)

(4)


Answer (4)


40.     On electrolysis of dil. sulphuric acid using Platinum (Pt) electrode, the product obtained at anode will be


(1) Oxygen gas

(2) H2S gas

(3) SO2 gas

(4) Hydrogen gas


Answer (1)


41.     What is the change in oxidation number of carbon in the following reaction?

CH4(g) + 4Cl2(g) → CCl4(l) + 4HCl(g)


(1) 0 to + 4

(2) – 4 to + 4

(3) 0 to – 4

(4) + 4 to + 4


Answer (2)


42.     Anisole on cleavage with HI gives

(1)

(2)

(3)

(4)


Answer (4)


43.     Measuring Zeta potential is useful in determining which property of colloidal solution?


(1) Solubility

(2) Stability of the colloidal particles

(3) Size of the colloidal particles

(4) Viscosity


Answer (2)


44.     Paper chromatography is an example of


(1) Partition chromatography

(2) Thin layer chromatography

(3) Column chromatography

(4) Adsorption chromatography


Answer (1)


45.     Match the following and identify the correct option.

(a)

CO(g) + H2(g)

(i)

Mg(HCO3)2 + Ca(HCO3)2

(b)

Temporary hardness of water

(ii)

An electron deficient hydride

(c)

B2H6

(iii)

Synthesis gas

(d)

H2O2

(iv)

Non-planar structure

 

 

(a)

(b)

(c)

(d)

(1)

(iii)

(ii)

(i)

(iv)

(2)

(iii)

(iv)

(ii)

(i)

(3)

(i)

(iii)

(ii)

(iv)

(4)

(iii)

(i)

(ii)

(iv)


Answer (4)


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