Practice Questions

Q31.Which one of the following statements for D.I. Mendeleeff, is incorrect ? (1) He authored the textbook - Principles of (2) At the time, he proposed Periodic Table of Chemistry. elements structure of atom was known. (3) Element with atomic number 101 is named after (4) He invented accurate barometer. him. JEE Main 2021 (22 Jul Shift 1) JEE Main Previous Year Paper

Q31.Complete combustion of 1. 80 g of an oxygen containing compound (CxHyOz) gave 2. 64 g of CO2 and 1. 08 g of H2O. The percentage of oxygen in the organic compound is : (1) 53. 33 (2) 50. 33 (3) 51. 63 (4) 63. 53

Q31.Identify the elements X and Y using the ionization energy values given below : Ionization energy (kJ / mol) 1st 2nd X 495 4563 Y 731 1450 (1) X = Na; Y = Mg (2) X = Mg; Y = F (3) X = Mg; Y = Na (4) X = F; Y = Mg

Q31.The absolute value of the electron gain enthalpy of halogens satisfies: (1) I > Br > Cl > F (2) Cl > Br > F > I (3) Cl > F > Br > I (4) F > Cl > Br > I

Q31.The correct order of electron gain enthalpy is: (1) S > O > Se > Te (2) O > S > Se > Te (3) S > Se > Te > O (4) Te > Se > S > O

Q31.Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R : Assertion A : The H −O −H bond angle in water molecule is 104. 5°. Reason R : The lone pair − lone pair repulsion of electrons is higher than the bond pair − bond pair repulsion. (1) A is false but R is true (2) Both A and R are true, but R is not the correct explanation of A (3) A is true but R is false (4) Both A and R are true, and R is the correct explanation of A

Q31.The unit of the van der Waals gas equation parameter ′a′ in (P + an2V2 )(V −nb) (1) dm3 mol−1 (2) kg ms−1 (3) atm dm6 mol−2 (4) kg ms−2

Q31.A certain orbital has no angular nodes and two radial nodes. The orbital is: (1) 2s (2) 3s (3) 3p (4) 2p JEE Main 2021 (18 Mar Shift 1) JEE Main Previous Year Paper

Q31.Given below are two statements: Statement I : Bohr's theory accounts for the stability and line spectrum of Li+ ion. Statement II : Bohr's theory was unable to explain the splitting of spectral lines in the presence of a magnetic field. In the light of the above statements, choose the most appropriate answer from the options given below: (1) Both statement I and statement II are true. (2) Statement I is false but statement II is true. (3) Both statement I and statement II are false. (4) Statement I is true but statement II is false. JEE Main 2021 (18 Mar Shift 2) JEE Main Previous Year Paper

Q31.Given below are two statements : Statement I : According to Bohr's model of an atom, qualitatively the magnitude of velocity of electron increases with decrease in positive charges on the nucleus as there is no strong hold on the electron by the nucleus. Statement II : According to Bohr's model of an atom, qualitatively the magnitude of velocity of electron increases with decrease in principle quantum number. In the light of the above statements, choose the most appropriate answer from the options given below: (1) Statement I is false but Statement II is true (2) Statement I is true but Statement II is false (3) Both Statement I and Statement II are false (4) Both Statement I and Statement II are true

Q31.Amongst the following, the linear species is: (1) NO2 (2) Cl2 O (3) O3 (4) N−3 JEE Main 2021 (17 Mar Shift 2) JEE Main Previous Year Paper

Q31.The orbital having two radial as well as two angular nodes is: (1) 5d (2) 4d (3) 4f (4) 3p

Q31.If the Thomson model of the atom was correct, then the result of Rutherford's gold foil experiment would have been: JEE Main 2021 (27 Jul Shift 2) JEE Main Previous Year Paper (1) All of the α -particles pass through the gold foil (2) α -particles are deflected over a wide range of without decrease in speed. angles. (3) All α -particles get bounced back by 180° . (4) α -particles pass through the gold foil deflected by small angles and with reduced speed.

Q31.According to Bohr's atomic theory: (A) Kinetic energy of electron is ∝Z2 . n2 (B) The product of velocity (v) of electron and principal quantum number (n), ′vn′∝Z2. (C) Frequency of revolution of electron in an orbit is ∝Z3 . n3 (D) Coulombic force of attraction on the electron is ∝Z3 . n4 Choose the most appropriate answer from the options given below: (1) (A), (C) and (D) only (2) (A) and (D) only (3) (C) only (4) (A) only

Q31.Which among the following species has unequal bond lengths? (1) SiF4 (2) SF4 (3) XeF4 (4) BF4

Q31.The ionic radii of K+, Na+, Al3 + and Mg2 + are in the order : (1) Na+ < K+ < Mg2 + < Al3 + (2) Al3 + < Mg2 + < K+ < Na+ (3) Al3 + < Mg2 + < Na+ < K+ (4) K+ < Al3 + < Mg2 + < Na+

Q31. The class of drug to which chlordiazepoxide with above structure belongs is : (1) Analgesic (2) Tranquillizer (3) Antacid (4) Antibiotic

Q32.Match List − I with List − II : List −I List −II (a) NaOH (i) Acidic (b) Be(OH)2 (ii) Basic (c) Ca(OH)2 (iii) Amphoteric (d) B(OH)3 (e) Al(OH)3 Choose the most appropriate answer from the options given below (1) (a) −(ii), (b) −(ii), (c) −(iii), (d) −(ii), (e) (2)−(iii)(a) −(ii), (b) −(iii), (c) −(ii), (d) −(i), (e) −(iii) (3) (a) −(ii), (b) −(ii), (c) −(iii), (d) −(i), (e) −(iii)(a)(4) −(ii), (b) −(i), (c) −(ii), (d) −(iii), (e) −(iii)

Q32.Hydrogen peroxide reacts with iodine in basic medium to give : (1) IO- (2) IO3- (3) I- (4) IO4-

Q32.Which one of the following is the correct PV vs P plot at constant temperature for an ideal gas ? ( P and V stand for pressure and volume of the gas respectively) (1) (2) (3) (4)

Q32.At 298 . 2 K the relationship between enthalpy of bond dissociation (in kJ mol-1) for hydrogen EH and its isotope, deuterium ED, is best described by: 1 (1) EH = 2ED (2) EH = ED (3) EH = ED - 7 . 5 (4) EH = 2ED JEE Main 2021 (25 Jul Shift 1) JEE Main Previous Year Paper

Q32.The compound/s which will show significant intermolecular H -bonding is/are : (1) (a), (b) and (c) (2) (b) only (3) (c) only (4) (a) and (b) only

Q32.The ionic radii of F− and O2− respectively are 1. 33 A and 1. 4A , while the covalent radius of N is 0. 74A The correct statement for the ionic radius of N3− from the following is : (1) It is smaller than F− and N (2) It is bigger than O2− and F− (3) It is bigger than F− and N, but smaller than of (4) It is smaller than O2− and F− , but bigger than of O2− N

Q32.In which one of the following sets all species show disproportionation reaction? (1) ClO4- , MnO4- , ClO2- and F2 (2) MnO42 - , ClO2- , Cl2 and Mn3 + (3) Cr2O72 - , MnO4- , ClO2- and Cl2 (4) ClO2- , F2, MnO4- and Cr2O72 -

Q32.The first ionization energy of magnesium is smaller, as compared to that of elements X and Y , but higher than that of Z. The elements X, Y and Z , respectively, are : (1) chlorine, lithium and sodium (2) argon, lithium and sodium (3) argon, chlorine and sodium (4) neon, sodium and chlorine