Practice Questions

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.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.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.Number of elements from the following that CANNOT form compounds with valencies which match with their respective group valencies is ______. B, C, N, S, O, F, P, Al, Si (1) 7 (2) 3 (3) 5 (4) 6

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

Q31.Which of the following cannot function as an oxidising agent? (1) N3 - (2) SO42 - (3) BrO3- (4) MnO4-

Q31.The density of ' x ' M solution (' X ' molar) of NaOH is 1.12 g mL−1 , while in molality, the concentration of the solution is 3 m(3molal). Then x is (Given : Molar mass of NaOH is 40 g/mol ) (1) 3.5 (2) 3.8 (3) 2.8 (4) 3.0

Q31.An organic compound has 42.1% carbon, 6.4% hydrogen and remainder is oxygen. If its molecular weight is 342, then its molecular formula is : (1) C11H18O12 (2) C12H20O12 (3) C12H22O11 (4) C14H20O10

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.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.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.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.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 metallic radius of Na is 1.86 A∘ and the ionic radius of Na+ is lesser than 1.86 A∘ . Statement II : Ions are always smaller in size than the corresponding elements. In the light of the above statements, choose the correct answer from the options given below : (1) Both Statement I and Statement II are false (2) Statement I is incorrect but Statement II is true (3) Both Statement I and Statement II are true (4) Statement I is correct but Statement II is false

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. List - I List - II (Elements) (Properties in their respective groups) A. Cl, S I. Elements with highest electronegativity B. Ge, As II. Elements with largest atomic size Match List I with List II Choose Elements which show properties of both C. Fr, Ra III. metals and non-metal Elements with highest negative electron D. F, O IV. gain enthalpy the correct answer from the options given below: (1) A-II, B-I, C-IV, D-III (2) A-III, B-II, C-I, D-IV (3) A-IV, B-III, C-II, D-I (4) A-II, B-III, C-IV, D-I

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

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.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

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.The electron affinity value are negative for A. Be →Be− B. N →N− C. O →O2− D. Na →Na− E. Al →Al− Choose the most appropriate answer from the options given below : (1) D and E only (2) A, B and C only (3) A and D only (4) A, B, D and E only

Q33.Consider the following elements. Which of the following is/are true about A', B', C' and D' ? A. Order of atomic radii: B' < A' < D' < C' B. Order of metallic character : B' < A' < D' < C' C. Size of the element : D' < C' < B' < A' D. Order of ionic radii : B'+ < A'+ < D'+ < C'+ Choose the correct answer from the options given below: (1) A only (2) A, B and D only (3) A and B only (4) B, C and D only

Q33.Choose the polar molecule from the following : (1) CCl4 (2) CO2 (3) CH2 = CH2 (4) CHCl3

Q33.Which one of the following molecules has maximum dipole moment? (1) NF3 (2) CH4 (3) PF5 (4) NH3