Practice Questions

Q31.Choose the Incorrect Statement about Dalton's Atomic Theory (1) chemical reactions involve reorganization of (2) Matter consists of indivisible atoms. atoms (3) Compounds are formed when atoms of different (4) Compounds are formed when atoms of different elements combine in any ratio. elements combine in any ratio. All the atoms of a given element have identical properties including identical mass.

Q31.The correct set of four quantum numbers for the valence electron of rubidium atom (Z = 37) is: (1) 5, 0, 0, + 12 (2) 5, 0, 1, + 12 (3) 5, 1, 0, + 12 (4) 5, 1, 1, + 12

Q31.The correct sequence of electron gain enthalpy of the elements listed below is A. Ar B. Br C. F D. S Choose the most appropriate from the options given below: (1) C > B > D > A (2) A > D > B > C (3) A > D > C > B (4) D > C > B > A

Q31.The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency ' A ' ×1012 hertz and that has a radiant intensity in that direction of ′ 1B′ watt per steradian. 'A' and 'B' are respectively (1) 540 and 683 (2) 450 and 683 (3) 450 and 1 (4) 540 and 1 683 683

Q31.Given below are two statements: Statement - I: Along the period, the chemical reactivity of the element gradually increases from group 1 to group 18 . Statement - II: The nature of oxides formed by group 1 element is basic while that of group 17 elements is acidic. In the the light above statements, choose the most appropriate from the questions given below: (1) Both statement I and Statement II are true. (2) Statement I is true but Statement II is False. (3) Statement I is false but Statement II is true. (4) Both Statement I and Statement II is false.

Q31.According to the wave-particle duality of matter by de-Broglie, which of the following graph plot presents most appropriate relationship between wavelength of electron λ and momentum of electron p ? JEE Main 2024 (01 Feb Shift 1) JEE Main Previous Year Paper (1) (2) (3) (4)

Q31.The number of moles of methane required to produce 11 gCO2( g) after complete combustion is : (Given molar mass of methane in gmol−1 : 16) (1) 0.35 (2) 0.5 (3) 0.75 (4) 0.25

Q31.Molality ( m ) of 3M aqueous solution of NaCl is : (Given : Density of solution = 1.25 g mL−1 , Molar mass in gmol−1 : Na −23, Cl −35.5) JEE Main 2024 (06 Apr Shift 2) JEE Main Previous Year Paper (1) 1.9 m (2) 3.85 m (3) 2.79 m (4) 2.90 m

Q31.Identify the correct statements about p-block elements and their compounds. (A) Non metals have higher electronegativity than metals. (B) Non metals have lower ionisation enthalpy than metals. (C) Compounds formed between highly reactive nonmetals and highly reactive metals are generally ionic. (D) The non-metal oxides are generally basic in nature. (E) The metal oxides are generally acidic or neutral in nature. Choose the correct answer from the options given below : (1) (B) and (D) only (2) (A) and (C) only (3) (D) and (E) only (4) (B) and (E) only

Q31.Match List I with List II Choose the correct answer from the options given below :- (1) A-II, B-III, C-I, D-IV (2) A-I, B-III, C-II, D-IV (3) A-II, B-IV, C-III, D-I (4) A-I, B-II, C-III, D-IV

Q31.A sample of CaCO3 and MgCO3 weighed 2 .21 g is ignited to constant weight of 1 .152 g. The composition of the mixture is: (Given molar mass in g mol−1, CaCO3: 100, MgCO3: 84) (1) 1 .187 𝑔 𝐶𝑎𝐶𝑂3 + 1 .023 𝑔 𝑀𝑔𝐶𝑂3 (2) 1 .023 𝑔 𝐶𝑎𝐶𝑂3 + 1 .023 𝑔 𝑀𝑔𝐶𝑂3 (3) 1 .187 𝑔 𝐶𝑎𝐶𝑂3 + 1 .187 𝑔 𝑀𝑔𝐶𝑂3 (4) 1 .023 𝑔 𝐶𝑎𝐶𝑂3 + 1 .187 𝑔 𝑀𝑔𝐶𝑂3

Q32.The correct order of first ionization enthalpy values of the following elements is : (A) O (B) N (C) Be (D) F (E) B Choose the correct answer from the options given below : (1) E < C < A < B < D (2) C < E < A < B < D (3) B < D < C < E < A (4) A < B < D < C < E

Q32.The molecular formula of second homologue in the homologous series of mono carboxylic acids is _________. (1) C3H6O2 (2) C2H4O2 (3) CH2O (4) C2H2O2

Q32.The correct order of the first ionization enthalpy is (1) Al > Ga > Tl (2) Ga > Al > B (3) Tl > Ga > Al (4) B > Al > Ga

Q32.Given below are the two statements: one is labeled as Assertion (A) and the other is labeled as Reason (R). JEE Main 2024 (30 Jan Shift 1) JEE Main Previous Year Paper Assertion (A): There is a considerable increase in covalent radius from N to P . However from As to Bi only a small increase in covalent radius is observed. Reason (R): covalent and ionic radii in a particular oxidation state increases down the group. In the light of the above statement, choose the most appropriate answer from the options given below: (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)

Q32.The linear combination of atomic orbitals to form molecular orbitals takes place only when the combining atomic orbitals A. have the same energy B. have the minimum overlap C. have same symmetry about the molecular axis D. have different symmetry about the molecular axis Choose the most appropriate from the options given below: (1) A, B, C only (2) A and C only (3) B, C, D only (4) B and D only

Q32.Which of the following electronic configuration would be associated with the highest magnetic moment ? (1) [Ar] 3d7 (2) [Ar] 3d8 (3) [Ar] 3d3 (4) [Ar] 3d6

Q32.Given below are two statements: Statement-I: Since fluorine is more electronegative than nitrogen, the net dipole moment of NF3 is greater than NH3. Statement-II: In NH3, the orbital dipole due to lone pair and the dipole moment of NH bonds are in opposite direction, but in NF3 the orbital dipole due to lone pair and dipole moments of N-F bonds are in same direction. In the light of the above statements. Choose the most appropriate from the options given below. (1) Statement I is true but Statement II is false. (2) Both Statement I and Statement II are false. (3) Both statement I and Statement II is are true. (4) Statement I is false but Statement II is are true.

Q32.The four quantum numbers for the electron in the outer most orbital of potassium (atomic no. 19) are (1) n = 4, l = 2, m = −1, s = + 1 (2) n = 4, l = 0, m = 0, s = + 1 2 2 1 1 (3) n = 3, l = 0, m = −1, s = + (4) n = 2, l = 0, m = 0, s = + 2 2

Q32.In case of isoelectronic species the size of F–, Ne and Na+ is affected by: (1) Principal quantum number n (2) None of the factors because their size is the same (3) Electron-electron interaction in the outer orbitals (4) Nuclear charge z

Q32.Given below are two statements : Statement (I) : Both metal and non-metal exist in $\mathrm{p}$ and d-block elements. Statement (II) : Non-metals have higher ionisation enthalpy and higher electronegativity than the metals. In the light of the above statements, choose the most appropriate answer from the option given below: (1) Both Statement I and Statement II are false (2) Statement I is false but Statement II is true (3) Statement I is true but Statement II is false (4) Both Statement I and Statement II are true

Q32.The element having the highest first ionization enthalpy is (1) Si (2) Al (3) N (4) C

Q32.Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R: Assertion A: The first ionisation enthalpy decreases across a period. Reason R: The increasing nuclear charge outweighs the shielding across the period. In the light of the above statements, choose the most appropriate from the options given below: (1) Both A and R are true and R is the correct (2) A is true but R is false explanation of A (3) A is false but R is true (4) Both A and R are true but R is NOT the correct explanation of A

Q32.Given below are two statements : Statement (I) : The oxidation state of an element in a particular compound is the charge acquired by its atom on the basis of electron gain enthalpy consideration from other atoms in the molecule. Statement (II) : pπ −pπ bond formation is more prevalent in second period elements over other periods. 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 correct (2) Both Statement I and Statement II are incorrect (3) Statement I is incorrect but Statement II is (4) Statement I is correct but Statement II is correct incorrect

Q32.The electronic configuration of Einsteinium is : (Given atomic number of Einsteinium = 99) (1) [Rn]5f 106 d∘7 s2 (2) [Rn]5f 136 d∘7 s2 (3) [Rn]5f 116 d∘7 s2 (4) [Rn]5f 126 d∘7 s2