Practice Questions
10,171 questions across 23 years of JEE Main — find and practise any topic!
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Q50.For the below given cyclic hemiacetal X, the correct pyranose structure is JEE Main 2022 (28 Jul Shift 1) JEE Main Previous Year Paper (1) (2) (3) (4)
Q50.The formulas of A and B for the following reaction sequence are (1) A = C7H14O8, B = C6H14 (2) A = C7H13O7, B = C7H14O (3) A = C7H12O8, B = C6H14 (4) A = C7H14O8, B = C6H14O6 Q51. 2 L of 0. 2 MH2 SO4 is reacted with 2 L of 0. 1 MNaOH solution, the molarity of the resulting product Na2 SO4 in the solution is____millimolar.
Q50.Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R. Assertion A : Amylose is insoluble in water. Reason R : Amylose is a long linear molecule with more than 200 glucose units. In the light of the above statements, choose the correct answer from the options given below. (1) Both A and R are correct and R is the correct (2) Both A and R are correct and R is NOT the explanation of A. correct explanation of A. (3) A is correct but R is not correct. (4) A is not correct but R is correct.
Q50.A polysaccharide ' X ' on boiling with dil H2 SO4 at 393 K under 2 −3 atm pressure yields ' Y ' ' Y ' on treatment with bromine water gives gluconic acid. ' X ' contains β -glycosidic linkages only. Compound ' X ' is : (1) starch (2) cellulose (3) amylose (4) amylopectin Q51. 2O3(g) ⇌3O2(g) At 300 K, ozone is fifty percent dissociated. The standard free energy change at this temperature and 1 atm pressure is (−). . . . . . J mol−1 . (Nearest integer) [Given: ln 1. 35 = 0. 3 and R = 8. 3 J K−1 mol−1 ]
Q50.Which of the following is reducing sugar? JEE Main 2022 (26 Jul Shift 1) JEE Main Previous Year Paper (1) (2) (3) (4)
Q50.Glycosidic linkage between C1 of α -glucose and C2 of β -fructose is found in (1) Maltose (2) Sucrose (3) Lactose (4) amylose Q51. 56. 0 L of nitrogen gas is mixed with excess of hydrogen gas and it is found that 20 L of ammonia gas is produced, The volume of unused nitrogen gas is found to be_____ L.
Q50.A sugar ' X ' dehydrates very slowly under acidic condition to give furfural which on further reaction with resorcinol gives the coloured product after sometime. Sugar ' X ' is (1) Aldopentose (2) Aldotetrose (3) Oxalic acid (4) Ketotetrose
Q50.Given below are two statements. Statement I: Maltose has two α −D −glucose units linked at C1 and C4 and is a reducing sugar. Statement II: Maltose has two monosaccharides: α - D-glucose and β - D-glucose linked at C1 and C6 and it is a non-reducing sugar. In the light of the above statements, choose the correct answer from the options Question: given below. (1) Both Statement I and Statement II are true. (2) Both Statement I and Statement II are false. (3) Statement I is true but Statement II is false. (4) Statement I is false but Statement II is true. Q51. 116 g of a substance upon dissociation reaction, yields 7. 5 g of hydrogen, 60 g of oxygen and 48. 5 g of carbon. Given that the atomic masses of H, O and C are 1, 16 and 12, respectively. The data agrees with how many formulae of the following? A. CH3 COOH B. HCHO C. CH3 OOCH3 D. CH3 CHO
Q50.Match List-I with List-II JEE Main 2022 (27 Jul Shift 2) JEE Main Previous Year Paper List-I List-II A Glucose + HI I Gluconic acid B Glucose + Br2 water II Glucose pentacetate C Glucose + acetic anhydride III Saccharic acid D Glucose + HNO3 IV Hexane Choose the correct answer from the options given below (1) A −IV, B −I, C −II, D −III (2) A −IV, B −III, C −II, D −I (3) A −III, B −I, C −IV, D −II (4) A −I, B −III, C −IV, D −II Q51. In the above reaction, 5 g of toluene is converted into benzaldehyde with 92% yield. The amount of benzaldehyde produced is____ ×10−2 g
Q50.Which statement is not true with respect to nitrate ion test? (1) A dark brown ring is formed at the junction of (2) Ring is formed due to nitroferrous sulphate two solutions. complex. (3) The brown complex is [Fe (H2O)5(NO)] SO4 (4) Heating the nitrate salt with conc. H2 SO4 , light brown fumes are evolved.
Q50.An antiseptic dettol is a mixture of two compounds 'A' and 'B' where A has 6π electrons and B has 2π electrons. What is B? (1) Bithional (2) Terpineol (3) Chlorophenol (4) Chloroxyenol
Q50.Which one of the following is a water soluble vitamin, that is not excreted easily? (1) Vitamin B2 (2) Vitamin B1 (3) Vitamin B6 (4) Vitamin B12 JEE Main 2022 (26 Jun Shift 2) JEE Main Previous Year Paper
Q51.At 300 K, a sample of 3. 0 g of gas A occupies the same volume as 0. 2 g of hydrogen at 200 K at the same pressure. The molar mass of gas A is g mol−1 . (nearest integer) Assume that the behaviour of gases as ideal. (Given: The molar mass of hydrogen (H2) gas is 2. 0 g mol−1 .)
Q51.The complete combustion of 0. 492 g of an organic compound containing ' C', ' H' and ' O' gives 0. 793 g of CO2 and 0. 442 g of H2O. The percentage of oxygen composition in the organic compound is____.(nearest integer) Q52. 100 g of an ideal gas is kept in a cylinder of 416 L volume at 27 °C under 1. 5 bar pressure. The molar mass of the gas is g mol−1 . (Nearest integer) (Given : R = 0. 083 L bar K−1 mol−1 )
Q51.A 1 . 84mg sample of polyhydric alcoholic compound 'X' of molar mass 92 . 0 g / mol gave 1 . 344 mL of H2 gas at STP. The number of alcoholic hydrogen present in compound 'X' is
Q51.Geraniol, a volatile organic compound, is a component of rose oil. The density of the vapour is 0. 46 gL−1 at 257 °C and 100 mmHg . The molar mass of geraniol is (Nearest Integer) [Given R = 0. 082 L atm K−1 mol−1 ] Q52. 17. 0 g of NH3 completely vapourises at −33. 42 °C and 1 bar pressure and the enthalpy change in the process is 23. 4 kJ mol−1 . The enthalpy change for the vapourisation of 85 g of NH3 under the same conditions is kJ.
Q51.Amongst the following the number of oxide(s) which are paramagnetic in nature is Na2 O, KO2, NO2, N2O, ClO2, NO, SO2, Cl2 O
Q51.A protein 'A' contains 0 . 30% of glycine (molecular weight 75). The minimum molar mass of the protein 'A' is____ × 103 g mol-1 [nearest integer] JEE Main 2022 (25 Jun Shift 2) JEE Main Previous Year Paper
Q51.Chlorophyll extracted from the crushed green leaves was dissolved in water to make 2 L solution of Mg of concentration 48ppm. The number of atoms of Mg in this solution is x × 1020 atoms. The value of x is (Nearest Integer) (Given : Atomic mass of Mg is 24 g mol−1 , NA = 6. 02 × 1023 mol−1 )
Q51.If the work function of a metal is 6. 63 × 10−19 J, the maximum wavelength of the photon required to remove a photoelectron from the metal is____ nm. Nearest integer) [Given : h = 6. 63 × 10−34 J s, and c = 3 × 108 m s−1 ]
Q51.The number of N atoms in 681 g of C7H5N3O6 is 𝑥× 1021. The value of x is NA = 6 . 02 × 1023 mol-1 (Nearest Integer) JEE Main 2022 (25 Jun Shift 1) JEE Main Previous Year Paper Q52.1 L aqueous solution of H2SO4 contains 0 . 02 m mol H2SO4 . 50% of this solution is diluted with deionized water to give 1 L solution A. In solution A, 0 . 01 m mol of H2SO4 are added. Total m mols of H2SO4 in the final solution is____ × 10-3 m moles.
Q51.Consider an imaginary ion 48X322 - . The nucleus contains 'a' % more neutrons than the number of electrons in the ion. The value of 'a' is
Q51.In the given reaction, X + Y + 3Z ⇄XYZ3 if one mole of each of X and Y with 0 . 05 mol of Z gives compound XYZ3. (Given : Atomic masses of X, Y and Z are 10,20 and 30amu, respectively). The yield of XYZ3 is____g.
Q51.If the uncertainty in velocity and position of a minute particle in space are, 2. 4 × 10−26(ms−1) and 10−7(m) respectively. The mass of the particle in g is___(Nearest integer) (Given : h = 6. 626 × 10−34 Js) Q52. 2 NOCl(g) ⇌2 NO(g) + Cl2(g) In an experiment, 2. 0 moles of NOCl was placed in a one-litre flask and the concentration of NO after equilibrium established, was found to be 0. 4 mol /L. The equilibrium constant at 30 °C is_____ ×10−4 .
Q51.A box contains 0. 90 g of liquid water in equilibrium with water vapour at 27°C. The equilibrium vapour pressure of water at 27°C 32. 0 Torr. When the volume of the box is increased, some of the liquid water evaporates to maintain the equilibrium pressure. If all the liquid water evaporates, then the volume of the box must be ______ litre. [nearest integer] (Given: R = 0. 082 L atm K−1 mol−1 _ (Ignore the volume of the liquid water and assume water vapours behave as an ideal gas.) Q52. 2. 2 g of nitrous oxide (N2O) gas is cooled at a constant pressure of 1 atm from 310 K to 270 K causing the compression of the gas from 217. 1 mL to 167. 75 mL. The change in internal energy of the process, △U is ′−x′J. The value of ′x′ is _____. [nearest integer] (Given: atomic mass of N = 14 g mol−1 and of O = 16 g mol−1 . Molar heat capacity of N2O is 100 JK−1 mol−1 )