JEE Main 2020 Chemistry Paper With Solutions Sept 3 (Shift 2)

JEE Main 2020 Paper With Solutions Chemistry - Shift 2 is a perfect resource to ace the upcoming JEE exams. Experts recommend candidates to solve JEE Main question papers before appearing for the examination. It will help the students to understand the type of questions asked, difficulty level, paper pattern and marking scheme. Solving JEE Main Previous Year Papers is very important for JEE Main preparation. It is designed to help the candidates to achieve their best scores and also assists in determining their weaker areas and identifying the gaps in exam-taking skills.

September 3 Shift 2 - Chemistry

Question 1: The five successive ionization enthalpies of an element are 800, 2427, 3658, 25024 and 32824 kJ mol–1. The number of valence electrons in the element is:

  1. 1) 2
  2. 2) 4
  3. 3) 3
  4. 4) 5

Solution:

  1. Answer: (3)

    Fourth & Fifth I.E. are very high (periodic properties) indicating the presence of three valence shell electrons.


Question 2: The incorrect statement is:

  1. 1) Manganate and permanganate ions are tetrahedral
  2. 2) In manganate and permanganate ions, the -bonding takes place by the overlap of p orbitals of oxygen and d-orbitals of manganese
  3. 3) Manganate and permanganate ions are paramagnetic
  4. 4) Manganate ion is green in colour and permanganate ion is purple in colour

Solution:

  1. Answer: (3)

    JEE Main 2020 Solved Paper Chemistry Shift 2 3rd Sept Ques 2


Question 3: Match the following drugs with their therapeutic actions:

(i) Ranitidine (a) Antidepressant

(ii) Nardil (Phenelzine) (b) Antibiotic

(iii)Chloramphenicol (c) Antihistamine

(iv) Dimetane (Brompheniramine) (d) Antacid

(e) Analgesic

  1. 1) (i)-(d); (ii)-(a); (iii)-(b); (iv)-(c)
  2. 2) (i)-(d); (ii)-(c); (iii)-(a); (iv)-(e)
  3. 3) (i)-(a); (ii)-(c); (iii)-(b); (iv)-(e)
  4. 4) (i)-(e); (ii)-(a); (iii)-(c); (iv)-(d)

Solution:

  1. Answer: (1)


Question 4: An ionic micelle is formed on the addition of

  1. 1) liquid diethyl ether to aqueous NaCl solution
  2. 2) sodium stearate to pure toluene
  3. 3) excess water to liquidJEE Main 2020 Solved Paper Chemistry Shift 2 3rd Sept Ques 4
  4. 4) excess water to liquidJEE Main 2020 Paper Chemistry Shift 2 3rd Sept Q4

Solution:

  1. Answer: (3)

    The ionic micelles formed by the addition of water to soap {sodium stearate}.


Question 5: Among the statements (I–IV), the correct ones are:

(I) Be has a smaller atomic radius compared to Mg.

(II) Be has higher ionization enthalpy than Al.

(III) Charge/radius ratio of Be is greater than that of Al.

(IV) Both Be and Al form mainly covalent compounds.

  1. 1) (I), (II) and (IV)
  2. 2) (I), (II) and (III)
  3. 3) (II), (III) and (IV)
  4. 4) (I), (III) and (IV)

Solution:

  1. Answer: (1)

    Refer S-Block


Question 6: Complex A has a composition of H12O6Cl3Cr. If the complex on treatment with conc. H2SO4 loses 13.5% of its original mass, the correct molecular formula of A is: [Given: the atomic mass of Cr = 52 amu and Cl = 35 amu]

  1. 1) [Cr(H2O)5Cl]Cl2 .H2O
  2. 2) [Cr(H2O)4Cl2]Cl.2H2O
  3. 3) [Cr(H2O)3Cl3].3H2O
  4. 4) [Cr(H2O)6]Cl3

Solution:

  1. Answer: (2)

    Let x molecule of water are lost then

    13.5 = {[x × 18] / [6 × 18 + 3 × 35 + 52]} * 100

    x = 1.99 ≃ 2


Question 7: The decreasing order of reactivity of the following compounds towards nucleophilic substitution (SN2) is:
JEE Main 2020 Solved Paper Chemistry Shift 2 3rd Sept Ques 7

  1. 1) (III) > (II) > (IV) > (I)
  2. 2) (IV) > (II) > (III) > (I)
  3. 3) (II) > (III) > (IV) > (I)
  4. 4) (II) > (III) > (I) > (IV)

Solution:

  1. Answer: (3)

    JEE Main 2020 Paper Chemistry Shift 2 3rd Sept Q7


Question 8: The increasing order of the reactivity of the following compounds in nucleophilic addition reaction is: Propanal, Benzaldehyde, Propanone, Butanone

  1. 1) Benzaldehyde < Propanal < Propanone < Butanone
  2. 2) Propanal < Propanone < Butanone < Benzaldehyde
  3. 3) Butanone < Propanone < Benzaldehyde < Propanal
  4. 4) Benzaldehyde < Butanone < Propanone < Propanal

Solution:

  1. Answer: (3)

    Rate of Nucleophilic addition Aldehyde > Ketone Aliphatic aldehyde > Aromatic aldehyde


Question 9: The major product in the following reaction is:
JEE Main 2020 Paper with Solutions Chemistry Shift 2 3rd Sept Q9

    Solution:

    1. Answer: (3)

      JEE Main 2020 Paper Chemistry Shift 2 3rd Sept Q9


    Question 10: The incorrect statement(s) among (a) – (d) regarding acid rain is (are):

    (a) It can corrode water pipes.

    (b) It can damage structures made up of stone.

    (c) It cannot cause respiratory ailments in animals

    (d) It is not harmful for trees

    1. 1) (a), (b) and (d)
    2. 2) (a), (c) and (d)
    3. 3) (c) and (d)
    4. 4) (c) only

    Solution:

    1. Answer: (3)

      Acid rain can cause respiratory ailments in animals and also harmful to trees and plants.


    Question 11: 100 mL of 0.1 M HCl is taken in a beaker and to it, 100 mL of 0.1 M NaOH is added in steps of 2 mL and the pH is continuously measured. Which of the following graphs correctly depicts the change in pH?
    JEE Main 2020 Paper with Solutions Chemistry Shift 2 3rd Sept Q11

      Solution:

      1. Answer: (3)

        JEE Main 2020 Paper Chemistry Shift 2 3rd Sept Q11

        initially pH will be acidic < 7

        at eq pH pH = 7

        & finally pH will be basic > 7

        JEE 2020 Paper Chemistry Shift 2 3rd Sept Question 11


      Question 12: Consider the hypothetical situation where the azimuthal quantum number, l, takes values 0, 1, 2, ...... n + 1, where n is the principal quantum number. Then, the element with atomic number:

      1. 1) 13 has a half-filled valence subshell
      2. 2) 9 is the first alkali metal
      3. 3) 8 is the first noble gas
      4. 4) 6 has a 2p-valence subshell

      Solution:

      1. Answer: (1)

        (1) 13X = 1s2 1p6 1d5 - half filled

        (2) 9X = 1s2 1p6 1d1 - not alkali metal

        (3) 8X = 1s2 1p6 - Second nobel gas


      Question 13: The d-electron configuration of [Ru(en)3]Cl2 and [Fe(H2O)6]Cl2, respectively are:

      1. 1) t42g e2g and t62g eog
      2. 2) t62g eog and t62g eog
      3. 3) t42g e2g and t42g e2g
      4. 4) t62g e0g and t42g e2g

      Solution:

      1. Answer: (4)

        JEE Main 2020 Solved Paper Chemistry Shift 2 3rd Sept Ques 13


      Question 14: Consider the following molecules and statements related to them:

      JEE Main 2020 Solved Paper Chemistry Shift 2 3rd Sept Ques 14

      (a) (B) is more likely to be crystalline than (A)

      (b) (B) has a higher boiling point than (A)

      (c) (B) dissolves more readily than (A) in water

      Identify the correct option from below:

      1. 1) (a) and (c) is true
      2. 2) only (a) is true (3) (b) and
      3. 3) are true
      4. 4) (a) and (b) are true

      Solution:

      1. Answer: All answers are correct.


      Question 15: The strengths of 5.6 volume hydrogen peroxide (of density 1 g/mL) in terms of mass percentage and molarity (M), respectively, are: (Take the molar mass of hydrogen peroxide as 34 g/mol)

      1. 1) 0.85 and 0.5
      2. 2) 0.85 and 0.25
      3. 3) 1.7 and 0.25
      4. 4) 1.7 and 0.5

      Solution:

      1. Answer: (4)

        Volume strength = 5.6V

        Molarity = [5.6 / 11.2] = 0.5 mol / l

        Mass % = [(0.5 × 34) / (10)] × [(1) / (1g / ml)]

        = 1.7%

        The answers are 1.7 & 0.5 that is option (4).


      Question 16: The compound A in the following reactions is:
      JEE Main 2020 Solved Paper Chemistry Shift 2 3rd Sept Ques 16

        Solution:

        1. Answer: (1)

          JEE Main 2020 Paper Chemistry Shift 2 3rd Sept Q16


        Question 17: A mixture of one mole each of H2, He and O2 each are enclosed in a cylinder of volume V at temperature T. If the partial pressure of H2 is 2 atm, the total pressure of the gases in the cylinder is:

        1. 1) 6 atm
        2. 2) 14 atm
        3. 3) 38 atm
        4. 4) 22 atm

        Solution:

        1. Answer: (1)

          pH2 = 2 atm = xH2 × ptotal

          2 atm = [(1) / (1 + 1 + 1] × ptotal

          ptotal = 6 atm


        Question 18: Three isomers A, B and C (mol. formula C8H11N) give the following results:
        JEE Main 2020 Solved Paper Chemistry Shift 2 3rd Sept Ques 18

          Solution:

          1. Answer: (2)

            JEE Main 2020 Paper Chemistry Shift 2 3rd Sept Q18


          Question 19: For the reaction 2A + 3B + (3 / 2) C → 3P, which statement is correct?

          1. 1) dnA / dt = dnB / dt = dnC / dt
          2. 2) dnA / dt = (3 / 2) dnB / dt = (3 / 4) dnC / dt
          3. 3) dnA / dt = (2 / 3) dnB / dt = (4 / 3) dnC / dt
          4. 4) dnA / dt = (2 / 3) dnB / dt = (3 / 4) dnC / dt

          Solution:

          1. Answer: (3)

            2A + 3B + (3 / 2) C → 3P JEE Main 2020 Paper with Solutions Chemistry Shift 2 3rd Sept Q19


          Question 20: Consider the following reaction:

          JEE Main 2020 Paper with Solutions Chemistry Shift 2 3rd Sept Q20

          The product 'P' gives positive ceric ammonium nitrate test. This is because of the presence of which of these –OH group(s)?

          1. 1) (b) only
          2. 2) (b) and (d)
          3. 3) (c) and (d)
          4. 4) (d) only

          Solution:

          1. Answer: (1)

            JEE Main 2020 Paper Chemistry Shift 2 3rd Sept Q20


          Question 21: The volume (in mL) of 0.1 N NaOH required to neutralise 10 mL of 0.1 N phosphinic acid is ___________.

            Solution:

            1. Answer: 10 ml

              NaOH + H3 PO2 NaH2PO2 + H2O

              Phosphinic

              Volume × 0.1 = 0.1 × 10

              Volume = 10 ml


            Question 22: An acidic solution of dichromate is electrolyzed for 8 minutes using 2A current. As per the following equation

            Cr2O72- + 14H+ + 6e– → 2Cr3++ + 7H2O

            The amount of Cr3+ obtained was 0.104 g. The efficiency of the process (in %) is (Take: F = 96000 C, At. mass of chromium = 52) _______.

              Solution:

              1. Answer: 60 %

                [moles of Cr3+] × 3 = [8 × 60 × 2] / 96000

                Moles of Cr3+ = [8 × 4] / 9600 = (1 / 300) mol

                Mass of Cr3+ = (52 / 300) g

                % efficiency = {[Actual obtained amount] / [Theoretical obtained amount]} * 100

                = [(0.104 / (52 / 100)) * 100]

                = 30 * (104 / 52)

                = 60%


              Question 23: If 250 cm3 of an aqueous solution containing 0.73 g of a protein A is isotonic with one litre of another aqueous solution containing 1.65 g of a protein B, at 298 K, the ratio of the molecular masses of A and B is ______ × 10–2 (to the nearest integer).

                Solution:

                1. Answer: 177

                  [0.73 / MA] × [1000 / 250] = 1.65 / MB

                  [MA / MB] = [73 × 4] / 165 = 1.769

                  = 176.9 × 10–2

                  = 177 × 10–2


                Question 24: 6.023 × 1022 molecules are present in 10 g of a substance 'x'. The molarity of a solution containing 5 g of substance 'x' in 2 L solution is _____ × 10–3.

                  Solution:

                  1. Answer: 25

                    Mol. wt of ‘x’ = {10 / [6.023 × 1022]} × 6.023 × 1023

                    M = [5 / 100] / 2 = [(5 / 200) * 1000] × 10-3

                    M = 25 × 10–3 mol/lit


                  Question 25: The number ofJEE Main 2020 Solved Paper Chemistry Shift 2 3rd Sept Ques 25groups present in a tripeptide Asp–Glu–Lys is ____.

                    Solution:

                    1. Answer: 5

                      JEE Main 2020 Paper Chemistry Shift 2 3rd Sept Q25


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