Practice Questions

Q48.On passing a gas, ' X ', through Nessler's reagent, a brown precipitate is obtained. The gas ' X ' is (1) H2S (2) CO2 (3) NH3 (4) Cl2

Q48.Match List – I with List –II. JEE Main 2024 (01 Feb Shift 1) JEE Main Previous Year Paper Choose the correct answer from options given below: (1) A - III, B - IV, C - I, D - II (2) A - IV, B - II, C - I, D - III (3) A - IV, B - II, C - III, D - I (4) A - III, B - IV, C - II, D - I

Q48.The correct statement regarding nucleophilic substitution reaction in a chiral alkyl halide is ; (1) Retention occurs in SNl reaction and inversion (2) Racemisation occurs in SNl reaction and occurs in SN2 reaction. retention occurs in SN2 reaction. (3) Racemisation occurs in both SN1 and SN2 (4) Racemisation occurs in SN1 reaction and reactions. inversion occurs in SN2 reaction.

Q49. Acid D formed in above reaction is: (1) Gluconic acid (2) Succinic acid (3) Oxalic acid (4) Malonic acid

Q49.Type of amino acids obtained by hydrolysis of proteins is : (1) β (2) α (3) δ (4) γ

Q49. Match List - I with List - II. Choose the correct answer from the options given below : (1) (A)-(IV), (B)-(II), (C)-(III), (D)-(I) (2) (A)-(I), (B)-(IV), (C)-(II), (D)-(III) (3) (A)-(III), (B)-(II), (C)-(I), (D)-(IV) (4) (A)-(II), (B)-(IV), (C)-(I), (D)-(III)

Q49.A reagent which gives brilliant red precipitate with Nickel ions in basic medium is (1) sodium nitroprusside (2) neutral FeCl3 (3) meta-dinitrobenzene (4) dimethyl glyoxime

Q50.Which structure of protein remains intact after coagulation of egg white on boiling? (1) Primary (2) Tertiary (3) Secondary (4) Quaternary

Q50.If one strand of a DNA has the sequence ATGCTTCA, sequence of the bases in complementary strand is: (1) CATTAGCT (2) TACGAAGT (3) GTACTTAC (4) ATGCGACT

Q50.Sugar which does not give reddish brown precipitate with Fehling's reagent is: JEE Main 2024 (30 Jan Shift 1) JEE Main Previous Year Paper (1) Sucrose (2) Lactose (3) Glucose (4) Maltose Q51. 0. 05 cm thick coating of silver is deposited on a plate of 0. 05 m2 area. The number of silver atoms deposited on plate are _______ ×1023 . (At mass Ag = 108, d = 7. 9 g cm−3) Round off to the nearest integer.

Q50. The incorrect statements regarding enzymes are : (A) Enzymes are biocatalysts. (B) Enzymes are non-specific and can catalyse different kinds of reactions. (C) Most Enzymes are globular proteins. (D) Enzyme - oxidase catalyses the hydrolysis of maltose into glucose. Choose the correct answer from the option given below : (1) (B), (C) and (D) (2) (B) and (D) (3) (A), (B) and (C) (4) (B) and (C)

Q50.Which of the following gives a positive test with ninhydrin? (1) Starch (2) Egg albumin (3) Polyvinyl chloride (4) Cellulose Q51. 9.3 g of pure aniline is treated with bromine water at room temperature to give a white precipitate of the product ' P '. The mass of product ' P ' obtaind is 26.4 g. The percentage yield is _______ % .

Q50.Coagulation of egg, on heating is because of : JEE Main 2024 (05 Apr Shift 2) JEE Main Previous Year Paper (1) The secondary structure of protein remains (2) Denaturation of protein occurs unchanged (3) Biological property of protein remains unchanged(4) Breaking of the peptide linkage in the primary structure of protein occurs

Q50.Two nucleotides are joined together by a linkage known as : (1) Phosphodiester linkage (2) Glycosidic linkage (3) Disulphide linkage (4) Peptide linkage

Q51.Wavenumber for a radiation having 5800Ã … wavelength is x × 10 cm−1 . The value of x is ________ (Integer answer)

Q51. A hypothetical electromagnetic wave is show below. The frequency of the wave is x × 1019 Hz . x = ______ (nearest integer)

Q51.The maximum number of orbitals which can be identified with n = 4 and ml = 0 is ______ JEE Main 2024 (04 Apr Shift 2) JEE Main Previous Year Paper

Q51.Volume of 3M NaOH (formula weight 40 g mol-1 ) which can be prepared from 84 g of NaOH is ____ × 10-1dm3. Q52.9 . 3 g of aniline is subjected to reaction with excess of acetic anhydride to prepare acetanilide. The mass of acetanilide produced if the reaction is 100% completed is _____ × 10-1 g. (Given molar mass in g mol-1 N = 14, O = 16, C = 12, H = 1 ) Q53.1 mole of PbS is oxidised by X moles of O3 to get Y moles of O2 . X + Y =

Q51.Number of moles of methane required to produce 22g CO2 ( g ) after combustion is x × 10 – 2 moles. The value of x is

Q51.Mass of methane required to produce 22 g of CO after complete combustion is g. (Given Molar mass in g mol- 1, C = 12. 0, H = 1. 0, O = 16. 0)

Q52.For hydrogen atom, energy of an electron in first excited state is −3.4eV, K. E. of the same electron of hydrogen atom is xeV . Value of x is ______ ×10−1eV . (Nearest integer)

Q53.When ΔHvap = 30 kJ/mol and ΔSvap = 75 J mol−1 K−1 , then the temperature of vapour, at one atmosphere is ______ K.

Q53.The total number of anti bonding molecular orbitals, formed from 2s and 2p atomic orbitals in a diatomic molecule is _____________.

Q53.For the reaction N2O4( g) ⇌2 NO2( g), Kp = 0. 492 atm at 300 K. Kc for the reaction at same temperature is ______ × 10−2 . (Given : R = 0. 082 L atm mol−1 K−1 )

Q53.The total number of molecular orbitals formed from 2s and 2p atomic orbitals of a diatomic molecule