This article includes :
In this article you will get all the question which are asked in Previous Year Questions. Solving Previous year question papers will give you the idea about the difficulty level of the Exam, Exam Pattern and Important Question. It is advised to each and every students that please solve at least last five year question. Probably 20-30 questions are directly asked from the these question papers. It will give you an advantage while attempting the question papers.
Previous year questions which were asked into the JEE Main (Chemistry)
Here you will find all the question which were asked into the previous year JEE Main Question Papers. A candidates who are preparing for JEE Main 2018 can take help from these questions because every year 20% question are directly taken from the previous year question papers.
1. If Z is a compressibility factor, van der Waals equation at low pressure can be written as :
- Z=1— Pb RT
- Z=1+ Pb RT
- Z=1+ RT Pb
- Z=1— a VRT
2. Which one of the following properties is not shown by NO ?
- It combines with oxygen to form nitrogen dioxide
- It’s bond order is 2.5
- It is diamagnetic in gaseous state
- It is a neutral oxide
3. The metal that cannot be obtained by electrolysis of an aqueous solution of its salts is :
4. Resistance of 0.2 M solution of an electrolyte is 50 K. The specific conductance of the solution is 1.4 S m 1. The resistance of 0.5 M solution of the same electrolyte is 280 K. The molar conductivity of 0.5 M solution of the electrolyte in S m2 mol—1 is :
5. CsCl crystallises in body centred cubic lattice. If ‘a’ is its edge length then which of the following expressions is correct ?
- r + + r —= 3 a Cs Cl 2
- rCs+ + rCl—= 3a
- rCs+ + rCl—= 3a
- r + + r —= 3a Cs Cl 2
6. Consider separate solutions of 0.500 M C2H5OH(aq), 0.100 M MgS(PO4)2(aq), 0.250 M KBr(aq) and 0.125 M NaSPO4(aq) at 25°C. Whick statement is true about tkese solutions, assuming all salts to be strong electrolytes ?
- 0.125 M NaSPO4(aq) Has the higkest osmotic pressure.
- 0.500 M C2H5OH(aq) has the higkest osmotic pressure.
- They all have the same osmotic pressure.
- 0.100 M MgS(PO4)2(aq) has the highest osmotic pressure.
7. Which of the following reactions H2O2 acts as a reducing agent ?
(a) H2O2+ 2H++2e—→ 2H2O
(b) H2O2—2e—→ O2+ 2H+
(c) H2O2+2e—→ 2OH—
(d) H2O2+ 2OH——2e—→ O2+2H2O
- (a), (c)
- (b), (d)
- (a), (b)
- (c), (d)
8. In SN2 reactions, the correct order of reactivity for the following compounds : CHSCl, CHSCH2Cl, (CHS)2CHCl and (CHS)SCCl is :
- CHSCH2Cl > CHSCl > (CHS)2CHCl > (CHS)SCCl
- (CHS)2CHCl > CHSCH2Cl > CHSCl > (CHS)SCCl
- CHSCl > (CHS)2CHCl > CHSCH2Cl > (CHS)SCCl
- CHSCl > CHSCH2Cl > (CHS)2CHCl > (CHS)SCCl
9. The octahedral complex of a metal ion MS+ with four monodentate ligands L1, L2, LS and L4 absorb wavelengths in the region of red, green, yellow and blue, respectively. The increasing order of ligand strength of the four ligands is :
- LS < L2 < L4 < L1
- L1 < L2< L4 < LS
- L4 < LS < L2 < L1
- L1 < LS < L2 < L4
10. For the estimation of nitrogen, 1.4 g of an organic compound was digested by Hjeldahl method and the evolved ammonia was absorbed in 60 mL of 10M sulphuric acid. The unreacted acid required 20 mL of M 10 sodium hydroxide for complete neutralisation. The percentage of nitrogen in the compound is :
- 3 %
- 5 %
- 6 %
11. The equivalent conductance of NaCl at concentration C and at infinite dilution are hC and hœ, respectively. The correct relationship between hC and hœ is given as : (where the constant B is positive)
- hC=hœ—(B) C
- hC=hœ+(B) C
12. In the reaction, CH3COOH —L—iA—lH—4 ‹A —P—Cl—5‹B —A—lc.—KO—H—‹C , the product C is :
- Acetyl ckloride
13. On heating an aliphatic primary amine with chloroform and ethanolic potassium hydroxide, the organic compound formed is :
- an alkyl cyanide
- an alkyl isocyanide
- an alhanol ‘
- an alhanediol
14. The correct statement for the molecule, CsIS , is :
- it contains CsS+ and I— ions.
- it contains Cs+, I— and lattice I2 molecule.
- it is a covalent molecule.
- it contains Cs+ and I— ions.
15. The equation which is balanced and represents the correct product(s) is :
- ]Mg(H 2 O) 6 ] 2 + + (EDTA) 4 — —e—xce—ss—Na—OH—‹ ]Mg(EDTA)] 2 + + 6H2O
- CuSO 4 + 4KCN → K 2 ]Cu(CN) 4 ] +K2SO4
- Li2O+2KCl → 2LiCl+K2O ‘
- ]CoCl(NH S) 5 ] ++ 5H + → Co 2 +
16. For the non – stoichiometre reaction 2A+B → C+D, the following kinetic data were obtained in three separate experiments, all at 298 K. Initial Concentration
(A) Initial Concentration
(B) Initial rate of formation of (mol L—S—) C 0.1 M 0.1 M 1.2 × 10—3 0.1 M 0.2 M 1.2 × 10—3 0.2 M 0.1 M 2.4 × 10—3 The rate law for the formation of C is :
- dc =k]A] ]B]2 dt
- dc =k]A] dt
- dc =k]A] ]B] dt
- dc =k]A]2 ]B]
17. Considering the basic strength of amines in aqueous solution, which one has the smallest phb value ?
18. Which one of the following bases is not present in DNA ?
19. The correct set of four quantum numbers for the valence electrons of rubidium atom (Z=37) is :
- 5, 1, 1, +
- 5, 0, 1, +
- 5, 0, 0, +
- 5, 1, 0, +
20. The major organic compound formed by the reaction of 1, 1, 1— hrichloroethane with silver powder is :
- 2 – Butyne
- 2 – Butene
21. The ratio of masses of oxygen and nitrogen in a particular gaseous mixture is 1 : 4. The ratio of number of their molecule is:
- 1 : 8
- 3 : 16
- 1 : 4
- 7 : 32
22. Whick one is classified as a condensation polymer ?
23.Among the following oxoacids, the correct decreasing order of acid strength is :
- HClO4 > HClOS > HClO2 > HOCl
- HClO2 > HClO4 > HClOS > HOCl
- HOCl > HClO2 > HClOS > HClO4
- HClO4 > HOCl > HClO2 > HClOS
24. For complete combustion of ethanol, C2H5OH(l)+3O2(g) → 2CO2(g)+3H2O(l), the amount of heat produced as measured in bomb calorimeter, is 1364.47 kJ mol—1 at 25°C. Assuming ideality the Enthalpy of combustion, AcH, for the reaction will be : (R=8.314 kJ mol—1)
- —1460.50 kJ mol—1
- —1350.50 kJ mol—1
- —1366.95 kJ mol—1
- —1361.95 kJ mol—1
25. The most suitable reagent for the conversion of R—CH2—OH→ R—CHO is :
- PCC (Pyridinium Chlorochromate)
1. The molecular formula of a commercial resin used for exchanging ions in water softening is C8H7SOSNa (Mol. wt. 206). What would be the maximum uptake of Ca2+ ions by the resin when expressed in mole per gram resin ?
2. Sodium metal crystallixes in a body centred cubic lattice with a unit cell edge of 4.29Å. The radius of sodium atom is approximately :
3. Which of the following is the energy of a possible excited state of hydrogen ?
- +13.6 eV
- —6.8 eV
- —3.4 eV
- +6.8 eV
4. The intermolecular interaction that is dependent on the inverse cube of distance between the molecules is :
- ion – ion interaction
- ion – dipole interaction
- London force
- Hydrogen bond
5. The vapour pressure of acetone at 20°C is 185 torr. When 1.2 g of a non-volatile substance was dissolved in 100 g of acetone at 20°C, its vapour pressure was 183 torr. The molar mass (g mol—1) of the substance is :
6. Two Faraday of electricity is passed through a solution of CuSO4. The mass of copper deposited at the cathode is : (at. mass of Cu=63.5 amu)
- 0 g
- 63.5 g
- 2 g
- 127 g
7. Higher order (>3) reactions are rare due to :
- low probability of simultaneous collision of all the reacting species
- increase in entropy and activation energy as more molecules are involved
- shifting of equilibrium towards reactants due to elastic collisions
- loss of active species on collision
8. 3 g of activated charcoal was added to 50 mL of acetic acid solution (0.06N) in a flask. After an hour it was filtered and the strength of the filtrate was found to be 0.042 N. The amount of acetic acid adsorbed (per gram of charcoal) is :
- 18 mg
- 36 mg
- 42 mg
- 54 mg
9. The ionic radii (in Å) of NS—, O2— and F— are respectively :
- 1.36, 1.40 and 1.71
- 1.36, 1.71 and 1.40
- 1.71, 1.40 and 1.36
- 1.71, 1.36 and 1.40
10. In the context of the Hall – Heroult process for the extraction of Al, which of the following statements is false ?
- CO and CO2 are produced in this process
- Al2OS is mixed with CaF2 which lowers the melting point of the mixture and brings conductivity
- AlS+ is reduced at the cathode to form Al
- NaSAlF6 serves as the electrolyte
11. From the following statements regarding H2O2, choose the incorrect statement :
- It can act only as an oxidizing agent
- It decomposes on exposure to light
- It has to be stored in plastic or wax lined glass bottles in dark
- It has to be kept away from dust
12. Which one of the following alkaline earth metal sulphates has its hydration enthalpy greater than its lattice enthalpy ?
13. Which among the following is the most reactive ?
14. Match the catalysts to the correct processes : Catalyst Process (A) TiClS (i) Wacker process (B) PdCl2 (ii) Ziegler – Natta polymerization (C) CuCl2 (iii) Contact process (D) V2O5 (iv) Deacon’s process
- (A) – (iii), (B) – (ii), (C) – (iv), (D) – (i)
- (A) – (ii), (B) – (i), (C) – (iv), (D) – (iii)
- (A) – (ii), (B) – (iii), (C) – (iv), (D) – (i)
- (A) – (iii), (B) – (i), (C) – (ii), (D) – (iv)
15. Which one has the highest boiling point ?
16. The number of geometric isomers that can exist for square planar ]Pt (Cl) (py) (NHS) (NH2OH)]+ is (py = pyridine) :
17. The color of KMnO4 is due to :
- M → L ckarge transfer transition
- d — d transition
- L → M ckarge transfer transition
- o — o* transition
18. Assertion : Nitrogen and Oxygen are the main components in the atmosphere but these do not react to form oxides of nitrogen. Reason : The reaction between nitrogen and oxygen requires high temperature.
- Both assertion and reason are correct, and the reason is the correct explanation for the assertion
- Both assertion and reason are correct, but the reason is not the correct explanation for the assertion
- The assertion is incorrect, but the reason is correct
- Both the assertion and reason are incorrect 19.
19. 19 In Carius method of estimation of halogens, 250 mg of an organic compound gave 141 mg of AgBr. The percentage of bromine in the compound is : (at. mass Ag=108; Br=80)
20. Which of the following compounds will exhibit geometrical isomerism ?
- 1 – Phenyl – 2 – butene
- 3 – Phenyl – 1 – butene
- 2 – Phenyl – 1 – butene
- 1, 1 – Diphenyl – 1 – propane
21. Thee synthesis of alkyl fluorides is best accomplished by :
- Free radical fluorination
- Sandmeyer’s reaction
- Finkelstein reaction
- Swarts reaction
22. Which polymer is used in the manufacture of paints and lacquers ?
- Poly vinyl chloride
23. Which of the vitamins given below is water soluble ?
- Vitamin C
- Vitamin D
- Vitamin E
- Vitamin K
24. Which of the following compounds is not an antacid ?
- Aluminium hydroxide
25. Which of the following compounds is not colored yellow ?
- (NH4)S ]As (MoS O1O)4]
1.Which one of the following statements about water is FALSE ?
- There is extensive intramolecular hydrogen bonding in the condensed phase.
- Ice formed by heavy water sinks in normal water.
- Water is oxidized to oxygen during photosynthesis.
- Water can act both as an acid and as a base.
2. In the Hofmann bromamide degradation reaction, the number of moles of NaOH and Br2 used per mole of amine produced are :
- Two moles of NaOH and two moles of Br2 .
- Four moles of NaOH and one mole of Br2 .
- One mole of NaOH and one mole of Br2 .
- Four moles of NaOH and two moles of Br2 .
3. Which of the following atoms has the highest first ionization energy ?
4. The concentration of fluoride, lead, nitrate and iron in a water sample from an underground lake was found to be 1000 ppb, 40 ppb, 100 ppm and 0.2 ppm, respectively. This water is unsuitable for drinking due to high concentration of :
6. The equilibrium constant at 298 K for a reaction A+B ⇌ C+D is 100. If the initial concentration of all the four species were 1 M each, then equilibrium concentration of D (in mol L−1) will be : 1.818
7. The absolute configuration of CO2H H OH H Cl CH3 is :
- (2S, 3S)
- (2R, 3R)
- (2R, 3S)
- (2S, 3R)
8. For a linear plot of log (x/m) versus log p in a Freundlich adsorption isotherm, which of the following statements is correct ? (k and n are constants)
- Only 1/n appears as the slope.
- log (1/n) appears as the intercept.
- Both k and 1/n appear in the slope term.
- 1/n appears as the intercept.
9. The distillation technique most suited for separating glycerol from spent-lye in the soap industry is :
- Steam distillation
- Distillation under reduced pressure
- Simple distillation
- Fractional distillation
10. Which of the following is an anionic detergent ?
- Cetyltrimethylammonium bromide
- Glyceryl oleate
- Sodium stearate
- Sodium lauryl sulphate
11.The species in which the N atom is in a state of sp hybridization is :
- NO+ 2
- NO− 2
12. Thiol group is present in :
13.Which one of the following ores is best concentrated by froth floatation method ?
14. Which of the following statements about low density polythene is FALSE ?
- Its synthesis requires oxygen or a peroxide initiator as a catalyst.
- It is used in the manufacture of buckets, dust-bins etc.
- Its synthesis requires high pressure.
- It is a poor conductor of electricity.
15. Which of the following compounds is metallic and ferromagnetic ?
16. At 300 K and 1 atm, 15 mL of a gaseous hydrocarbon requires 375 mL air containing 20% O2 by volume for complete combustion. After combustion the gases occupy 330 mL. Assuming that the water formed is in liquid form and the volumes were measured at the same temperature and pressure, the formula of the hydrocarbon is :
17. The pair in which phosphorus atoms have a formal oxidation state of +3 is : Orthophosphorous and hypophosphoric acids
- Pyrophosphorous and pyrophosphoric acids
- Orthophosphorous and pyrophosphorous acids
- Pyrophosphorous and hypophosphoric acids
18. The reaction of propene with HOCl (Cl2+H2O) proceeds through the intermediate : CH3−CH(OH)−CH+ +
19. Which one of the following complexes shows optical isomerism ?
20. The main oxides formed on combustion of Li, Na and K in excess of air are, respectively :
- Li2O2, Na2O2 and KO2
- Li2O, Na2O2 and KO2
- Li2O, Na2O and KO2
- LiO2, Na2O2 and K2O
21. The reaction of zinc with dilute and concentrated nitric acid, respectively, produces :
- NO and N2O
- NO2 and N2O
- N2O and NO2
- NO2 and NO
1. Among the following, correct statement is :
- Brownian movement is more pronounced for smaller particles than for bigger–particles.
- Sols of metal sulphides are lyophilic.
- Hardy Schulze law states that bigger the size of the ions, the greater is its coagulating power.
- One would expect charcoal to absorb chlorine more than hydrogen sulphide.
2. Excess of NaOH (aq) was added to 100mL of FeCl3 (aq) resulting into 2.14 g of Fe(OH). The molarity of FeCl3 (aq) is : (Given molar mass of Fe=56 g mol−1 and molar mass of Cl=35. 5 g mol−1) 0.2 M 0.3 M 0.6 M 1.8 M 3. Among the following, the incorrect statement is :
- At low pressure, real gases show ideal behaviour.
- At very low temperature, real gases show ideal behaviour.
- At very large volume, real gases show ideal behaviour.
- At Boyle’s temperature, real gases show ideal behaviour.
3. For a reaction, A(g) A(l); ∆H=−3RT.
The correct statement for the reaction is :
- |∆H| < |∆U|
- |∆H| > |∆U|
4. 5g of Na2SO4 was dissolved in x g of H2O. The change in freezing point was found to be 3.82°C. If Na2SO4 is 81.5% ionised, the value of x (Kf for water=1.86°C kg mol−1) is approximately : (molar mass of S=32 g mol−1 and that of Na=23 g mol−1)
- 15 g
- 25 g
- 45 g
- 65 g
5. Addition of sodium hydroxide solution to a weak acid (HA) results in a buffer of pH 6. If ionisation constant of HA is 10−5, the ratio of salt to acid concentration in the buffer solution will be :
- 4 : 5
- 1 : 10
- 10 : 1
- 5 : 4
6. The rate of a reaction A doubles on increasing the temperature from 300 to 310 K. By how much, the temperature of reaction B should be increased from 300 K so that rate doubles if activation energy of the reaction B is twice to that of reaction A.
- 9.84 K
- 4.92 K
- 2.45 K
- 19.67 K
7. Which of the following is paramagnetic ?
- CO 2−
8. sp3d2 hybridization is not displayed by :
9. Identify the pollutant gases largely responsible for the discoloured and lustreless nature of marble of the Taj Mahal.
- O3 and CO2
- CO2 and NO2
- SO2 and NO2
- SO2 and O3
10. A metal ‘M’ reacts with nitrogen gas to afford ‘M3N’. ‘M3N’ on heating at high temperature gives back ‘M’ and on reaction with water produces a gas ‘B’. Gas ‘B’ reacts with aqueous solution of CuSO4 to form a deep blue compound. M and B respectively are:
- Li and NH3
- Ba and N2
- Na and NH3
- Al and N2
11. The number of S=O and S−OH bonds present in peroxodisulphuric acid and pyrosulphuric acid respectively are :
- (2 and 2) and (2 and 2)
- (2 and 4) and (2 and 4)
- (4 and 2) and (2 and 4)
- (4 and 2) and (4 and 2)
12. A solution containing a group-IV cation gives a precipitate on passing H2S. A solution of this precipitate in dil.HCl produces a white precipitate with NaOH solution and bluish-white precipitate with basic potassium ferrocyanide. The cation is :
13. The reason for “drug induced poisoning” is :
- Binding reversibly at the active site of the enzyme
- Bringing conformational change in the binding site of enzyme
- Binding irreversibly to the active site of the enzyme
- Binding at the allosteric sites of the enzyme
14. Among the following, the essential amino acid is :
- Aspartic acid
15. Which of the following statements is not true about partition chromatography ?
- Mobile phase can be a gas
- Stationary phase is a finely divided solid adsorbent
- Separation depends upon equilibration of solute between a mobile and a stationary phase Paper chromatography is an example of partition chromatography
16. The IUPAC name of the following compound is :
- 1,1 -Dimethyl-2-ethylcyclohexane
- 2, 2-Dimethyl-1-ethylcyclohexane
All the Very Best!!!!!!