Practice Questions

Q49.The rate constant for a first order reaction is 20 min−1 . The time required for the initial concentration of the reactant to reduce to its 1 level is ______ × 10−2 min . (Nearest integer) 32

Q49.The correct representation in six membered pyranose form for the following sugar [X] is JEE Main 2023 (01 Feb Shift 1) JEE Main Previous Year Paper (1) (2) (3) (4)

Q49.The statement/s which are true about antagonists from the following is/are: A. They bind to the receptor site. B. Get transferred inside the cell for their action. C. Inhibit the natural communication of the body. D. Mimic the natural messenger. Choose the correct answer from the options given below: (1) B only (2) A, C and D (3) A and C (4) A and B

Q49.In the wet tests for detection of various cations by precipitation, Ba2 + cations are detected by obtaining precipitate of (1) Ba(ox) : Barium oxalate (2) BaCO3 (3) Ba ( OAc ) 2 (4) BaSO4

Q49.Buna - S can be represented as: (1) (2) (3) (4) JEE Main 2023 (10 Apr Shift 2) JEE Main Previous Year Paper

Q49.The number of correct statements about modern adsorption theory of heterogeneous catalysis from the following is ...... A. The catalyst is diffused over the surface of reactants. B. Reactants are adsorbed on the surface of the catalyst. C. Occurrence of chemical reaction on the catalyst's surface through formation of an intermediate. D. It is a combination of intermediate compound formation theory and the old adsorption theory. E. It explains the action of the catalyst as well as those of catalytic promoters and poisons.

Q49.The graph of log mx vs log p for an adsorption process is a straight line inclined at an angle of 45° with intercept equal to 0. 6020 . The mass of gas adsorbed per unit mass of adsorbent at the pressure of 0. 4 atm is JEE Main 2023 (30 Jan Shift 2) JEE Main Previous Year Paper _____ ×10−1 (Nearest integer) Given : log 2 = 0. 3010

Q49.Compound X undergoes following sequence of reactions to give the Lactone Y. (1) (2) (3) (4)

Q49.Which of the following metals can be extracted through alkali leaching technique? (1) Sn (2) Pb (3) Au (4) Cu JEE Main 2023 (08 Apr Shift 1) JEE Main Previous Year Paper

Q49.Which of the following artificial sweeteners has the highest sweetness value in comparison to cane sugar? (1) Aspartame (2) Sucralose (3) Alitame (4) Saccharin

Q49. A →B The above reaction is of zero order. Half life of this reaction is 50 min . The time taken for the concentration of A to reduce to one-fourth of its initial value is min . (Nearest integer)

Q49.Match List-I with List-II. List-I Polymer List-II Type/Class A. Nylon-2-Nylon-6 I. Thermosetting polymer B. Buna-N II. Biodegradable polymer C. Ureaformaldehyde resin III. Synthetic rubber D. Dacron IV. Polyester Choose the correct answer from the options given below: (1) A →IV; B →I; C →II; D →II (2) A →II; B →III; C →I; D →IV (3) A →IV; B →III; C →I; D →II (4) A →II; B →I; C →IV; D →III

Q49.Consider the following reaction that goes from A to B in three steps as shown below: Choose the correct option Number of Rate Number of Activated determining Intermediates Complexes step (1) 2 3 I (2) 2 3 III (3) 2 3 II (4) 3 2 II (1) (1) (2) (2) (3) (3) (4) (4)

Q49.Match List I with List II: List I (Monomer) List II (Polymer) (A) Tetrafluoroethene (I) Orlon (B) Acrylonitrile (II) Natural rubber (C) Caprolactam (III) Teflon (D) Isoprene (IV) Nylon- 6 Choose the correct answer from the options given below: (1) (A) −(III), (B) −(I), (C) −(IV), (D) −(II) (2) (A) −(IV), (B) −(I), (C) −(II), (D) −(III) (3) (A) −(III), (B) −(IV), (C) −(II), (D) −(I) (4) (A) −(II), (B) −(III), (C) −(IV), (D) −(I)

Q49.The metal which is extracted by oxidation and subsequent reduction from its ore is : (1) Al (2) Ag (3) Cu (4) Fe

Q49.Inert gases have positive electron gain enthalpy. Its correct order is (1) Xe < Kr < Ne < He (2) He < Ne < Kr < Xe (3) He < Xe < Kr < Ne (4) He < Kr < Xe < Ne JEE Main 2023 (25 Jan Shift 1) JEE Main Previous Year Paper

Q49.In the wet tests for identification of various cations by precipitation, which transition element cation doesn't belong to group IV in qualitative inorganic analysis? (1) Fe3 + (2) Zn2 + (3) Co2 + (4) Ni2 +

Q49.For certain chemical reaction X →Y , the rate of formation of product is plotted against the time as shown in the figure. The number of Correct statement/s from the following is _____ (A) Over all order of this reaction is one (B) Order of this reaction can't be determined (C) In region-I and III, the reaction is of first and zero order respectively (D) In region-II, the reaction is of first order (E) In region-II, the order of reaction is in the range of 0. 1 to 0. 9. JEE Main 2023 (29 Jan Shift 1) JEE Main Previous Year Paper

Q49.The reaction 2NO + Br2 →2 NOBr takes place through the mechanism given below NO + Br2 ⇌NOBr2 (fast) NOBr2 + NO →2 NOBr (slow) The overall order of the reaction is _____.

Q50.A solution of CrO5 in amyl alcohol has a....colour (1) Green (2) Orange-Red (3) Yellow (4) Blue

Q50.Given below are two statements: Statement I: During Electrolytic refining, the pure metal is made to act as anode and its impure metallic form is used as cathode. Statement II: During the Hall-Heroult electrolysis process, purified Al2 O3 is mixed with Na3 AlF6 to lower the melting point of the mixture. In the light of the above statements, choose the most appropriate answer from the options given below: (1) Statement I is incorrect but Statement II is (2) Both Statement I and Statement II are incorrect correct (3) Statement I is correct but Statement II is (4) Both Statement I and Statement II are correct incorrect

Q50.Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Ketoses give Seliwanoff’s test faster than Aldoses. Reason (R): Ketoses undergo 𝛽-elimination followed by formation of furfural. In the light of the above statements, choose the correct answer from the options given below: (1) (A) is false but (R) is true (2) Both (A) and (R) are true and (R) is the correct explanation of (A) (3) (A) is true but (R) is false (4) Both (A) and (R) are true but (R) is not the correct explanation of (A)

Q50.The polymer X-consists of linear molecules and is closely packed. It is prepared in the presence of trimethylammoniumpropyl and titanium tetrachloride under low pressure. The polymer X is (1) High density polythene (2) Polyacrylonitrile (3) Low density polythene (4) Polytetrafluoroethane

Q50.Match List I with List II List I List II A Physisorption I Single Layer Adsorption B Chemisorption II 20 −40 kJ mol−1 Fe(s) C III Chromatography− N2(g) + 3H2(g) → 2 NH3(g) D Analytical Application or Adsorption IV Heterogeneous catalysis Choose the correct answer from the options given below: (1) A-III, B-IV, C-I, D-II (2) A-II, B-III, C-I, D-IV (3) A-II, B-I, C-IV, D-III (4) A-IV, B-II, C-III, D-I

Q50.The one that does not stabilize 2∘ and 3∘ structures of proteins is (1) – S – S – linkage (2) H - bonding (3) – O – O – linkage (4) van der Waals forces