Practice Questions

Q38.The decreasing order of hydride affinity for following carbocations is: (a) (2) (3) (4) Choose the correct answer from the options given below: (1) C, A, D, B (2) C, A, B, D (3) A, C, D, B (4) A, C, B, D

Q38.In sulphur estimation. 0. 471 g of an organic compound gave 1. 4439 g of barium sulphate. The percentage of sulphur in the compound is _______(Nearest Integer) (Given: Atomic mass Ba: 137u : S : 32u, O : 16u )

Q38.Adding surfactants in non polar solvent, the micelles structure will look like (a) (b) JEE Main 2023 (31 Jan Shift 1) JEE Main Previous Year Paper (c) (d) (1) b (2) c (3) a (4) d

Q38.During the reaction of permanganate with thiosulphate, the change in oxidation of manganese occurs by value of 3. Identify which of the below medium will favour the reaction. (1) Both aqueous acidic and neutral (2) Aqueous neutral (3) Both aqueous acidic and faintly alkaline (4) Aqueous acidic

Q38.Decreasing order of reactivity towards electrophilic substitution for the following compounds is: (1) d > a > e > c > b (2) e > d > a > b > c (3) a > d > e > b > c (4) c > b > a > d > e

Q39.The major product 'P' formed in the given reaction is JEE Main 2023 (10 Apr Shift 1) JEE Main Previous Year Paper (1) (2) (3) (4)

Q39.Identify the correct statements about alkali metals. A. The order of standard reduction potential (M+ | M) for alkali metal ions is Na > Rb > Li. B. CsI is highly soluble in water. C. Lithium carbonate is highly stable to heat. D. Potassium dissolved in concentrated liquid ammonia is blue and paramagnetic. E. All alkali metal hydrides are ionic solids. Choose the correct answer from the options given below (1) A, B, D only (2) C and E only (3) A and E only (4) A, B and E only

Q39.Arrange the following compounds in increasing order of rate of aromatic electrophilic substitution reaction. (1) d, b, c, a (2) d, b, a, c (3) b, c, a, d (4) c, a, b, d

Q39.Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Gypsum is used for making fireproof wall boards. Reason (R): Gypsum is unstable at high temperatures. In the light of the above statements, choose the correct answer from the options given below: (1) Both (A) and (R) are correct but (R) is not the (2) (A) is correct but (R) is not correct. correct explanation of (A). (3) (A) is not correct but (R) is correct. (4) Both (A) and (R) are correct and (R) is the correct explanation of (A).

Q39.Boric acid in solid, whereas BF3 is gas at room temperature because of (1) Strong ionic bond in Boric acid (2) Strong van der Waal's interaction in Boric acid (3) Strong hydrogen bond in Boric acid (4) Strong covalent bond in BF3

Q39.The magnetic behaviour of Li2 O, Na2 O2 and KO2 , respectively, are (1) diamagnetic, paramagnetic and diamagnetic (2) paramagnetic, paramagnetic and diamagnetic (3) paramagnetic, diamagnetic and paramagnetic (4) diamagnetic, diamagnetic and paramagnetic

Q39.Alkali metal from the following with least melting point is (1) Cs (2) Rb (3) Na (4) K

Q39.Match List I with List II List I List II Type of Hydride Example A Electron deficient hydride I MgH2 B Electron rich hydride II HF C Electron precise hydride III B2H6 D Saline hydride IV CH4 Choose the correct answer from the options given below : (1) A-III, B-II, C-IV, D-I (2) A-II, B-III, C-I, D-IV (3) A-II, B-III, C-IV, D-I (4) A-III, B-II, C-I, D-IV

Q39.Which of the following represents the correct order of metallic character of the given elements? (1) Si < Be < Mg < K (2) Be < Si < Mg < K (3) K < Mg < Be < Si (4) Be < Si < K < Mg

Q39.The methods NOT involved in concentration of ore are (A) Liquation (B) Leaching (C) Electrolysis (D) Hydraulic washing (E) Froth floatation Choose the correct answer from the options given below: (1) B, D and C only (2) C, D and E only (3) A and C only (4) B, D and E only

Q39.The standard electrode potential of M+ / M in aqueous solution does not depend on (1) Hydration of a gaseous metal ion (2) Sublimation of a solid metal (3) Ionisation of a solid metal atom (4) Ionisation of a gaseous metal atom

Q40.In the given reaction cycle X, Y and Z respectively are (1) X −CaCO3, Y −NaCl, Z −KCl (2) X −CaCO3, Y −NaCl, Z −HCl (3) X −CaO, Y −NaCl + CO2, Z −NaCl (4) X −CaO, Y −NaCl + CO2, Z −KCl

Q40.When a hydrocarbon A undergoes combustion in the presence of air, it requires 9. 5 equivalents of oxygen and produces 3 equivalents of water. What is the molecular formula of A ? JEE Main 2023 (29 Jan Shift 2) JEE Main Previous Year Paper (1) C8H6 (2) C9H9 (3) C6H6 (4) C9H6

Q40.The most stable carbocation for the following is: (1) c (2) d (3) b (4) a

Q40.In the extraction of copper, its sulphide ore is heated in a reverberatory furnace after mixing with silica to: (1) separate CuO as CuSiO3 (2) remove calcium as CaSiO3 (3) decrease the temperature needed for roasting of (4) remove FeO as FeSiO3 Cu2S

Q40.In Carius tube, an organic compound ' X ' is treated with sodium peroxide to form a mineral acid ' Y '. The solution of BaCl2 is added to ' Y ' to form a precipitate ' Z '. ' Z ' is used for the quantitative estimation of an JEE Main 2023 (10 Apr Shift 2) JEE Main Previous Year Paper extra element. ' X ' could be (1) Cytosine (2) A nucleotide (3) Methionine (4) Chloroxylenol

Q40.Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R Assertion A :- Carbon forms two important oxides CO and CO2 . CO is neutral whereas CO2 is acidic in nature. Reason R : CO2 can combine with water in a limited way to form carbonic acid, while CO is sparingly soluble in water. In the light of the above statements, choose the most appropriate answer from the options given below :- (1) Both A and R are correct but R is NOT the (2) Both A and R are correct and R is the correct correct explanation of A. explanation of A. (3) A is not correct but R is correct. (4) A is correct but R is not correct.

Q40.Identify X, Y and Z in the following reaction. (Equation not balanced) H2O Cl ∙O + NO2 →X ⟶Y + Z ¯ ¯ ¯ (1) X = ClONO2, Y = HOCl, Z = NO2 (2) X = ClNO2, Y = HCl, Z = HNO3 (3) X = ClONO2, Y = HOCl, Z = HNO3 (4) X = ClNO3, Y = Cl2, Z = NO2

Q40. The correct sequence of reagents for the preparation of Q and R is: (1) (i) Cr2 O3, 770 K, 20 atm ; (ii) (2) (i) CrO2 Cl2, H3O+ ; (ii) CrO2 Cl2, H3O+ ; (iii) NaOH ; (iv) H3O+ Cr2 O3, 770 K, 20 atm; (iii) NaOH; (iv) H3O+ (3) (i) KMnO4, OH− ; (ii) Mo2 O3, Δ; (iii) NaOH; (4) (i) Mo2 O3, Δ; (ii) CrO2 Cl2, H3O+ ; (iii) (iv) H3O+ NaOH; (iv) H3O+

Q40.Match List I with List II. List I List II A. Reverberatory furnace I. Pig iron B. Electrolytic cell II. Aluminium C. Blast furnace III. Silicon D. Zone refining furnace IV. Copper JEE Main 2023 (24 Jan Shift 1) JEE Main Previous Year Paper (1) A - IV, B - II, C - I, D - III (2) A - I, B - IV, C - II, D - III (3) A - I, B - III, C - II, D - IV (4) A - III, B - IV, C - I, D - II