Practice Questions

Q35.Reaction of BeO with ammonia and hydrogen fluoride gives 'A' which on thermal decomposition gives BeF2 and NH4F. What is 'A' ? (1) H3NBeF3 (2) NH42BeF4 (3) NH4BeF3 (4) NH42Be2F6

Q35.Match List-I with List-II: List-I Species List-II Geometry/Shape A. H3O+ I. Tetrahedral B. Acetylide anion II. Linear C. NH4+ III. Pyramidal D. ClO2- IV. Bent Choose the correct answer from the options given below: (1) A(III), B(IV), C(I), D(II) (2) A(III), B(I), C(II), D(IV) (3) A(III), B(II), C(I), D(IV) (4) A(III), B(IV), C(II), D(I)

Q35.Given (A) 2COg + O2g →2CO2g ΔH1o = - x kJ mol-1 (B) Cgraphite + O2g →CO2g ΔH2o = - y kJ mol-1 1 The ∆Ho for the reaction Cgraphite + 2O2g →COg is (1) 2x - y (2) x + 2y 2 2 x - 2y (3) (4) 2y - x 2

Q35.At 298 K N2(g) + 3H2(g) ⇌2 NH3(g), K1 = 4 × 105 N2(g) + O2(g) ⇌2 NO(g), K2 = 1. 6 × 1012 H2(g) + 12 O2(g) ⇌H2O(g), K3 = 1. 0 × 10−13 Based on above equilibria, the equilibrium constant of the reaction, 2 NH3(g) + 25 O2( g) ⇌2 NO(g) + 3H2O(g) is _____ ×10−33 (Nearest integer)

Q35.Consider the following equation: 2 SO2(g) + O2(g) ⇌2 SO3(g), ΔH = −190 kJ. The number of factors which will increase the yield of SO3 at equilibrium from the following is _____ . A. Increasing temperature B. Increasing pressure C. Adding more SO2 D. Adding more O2 E. Addition of catalyst

Q35.Consider the following reaction approaching equilibrium at 27°C and 1 atm pressure Kt=03 A + B ⇌ C + D Kr=102 The standard Gibb's energy change (ΔrG°) at 27°C is (−) _____ kJmol−1 (Nearest integer). (Given : R = 8. 3J K−1 mol−1 and ln 10 = 2. 3 )

Q35.Given below are two statements: Statement I: SbCl5 is more covalent than SbCl3 Statement II: The higher oxides of halogens also tend to be more stable than the lower ones. In the light of the above statements, choose the most appropriate answer from the options given below. (1) Statement I is incorrect but statement II is correct (2) Both Statement I and Statement II are incorrect (3) Both Statement I and Statement II are correct (4) Statement I is correct but statement II is incorrect

Q35. ClF5 at room temperature is a (1) Colourless liquid with trigonal (2) Colourless gas with square pyramidal geometry bipyramidal geometry (3) Colourless gas with trigonal bipyramidal (4) Colourless liquid with square pyramidal geometry geometry

Q36. Three bulbs are filled with CH4, CO2 and Ne as shown in the picture. The bulbs are connected through pipes of zero volume. When the stopcocks are opened and the temperature is kept constant throughout, the pressure of the system is found to be______ atm. (Nearest integer).

Q36.Match List I with List II List I List II Elements Colour imparted to the flame A K I Brick Red B Ca II Violet C Sr III Apple Green D Ba IV Crimson Red Choose the correct answer from the options given below: (1) A-II, B-I, C-III, D-IV (2) A-II, B-IV, C-I, D-III (3) A-II, B-I, C-IV, D-III (4) A-IV, B-III, C-II, D-I

Q36.Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). JEE Main 2023 (30 Jan Shift 1) JEE Main Previous Year Paper Assertion (A): In expensive scientific instruments, silica gel is kept in watch-glasses or in semipermeable membrane bags. Reason (R): Silica gel adsorbs moisture from air via adsorption, thus protects the instrument from water corrosion (rusting) and / or prevents malfunctioning. In the light of the above statements, choose the correct answer from the options given below: (1) (A) is false but (R) is true (2) (A) is true but (R) is false (3) Both (A) and (R) are true and (R) is the correct (4) Both (A) and (R) are true but (R) is not the explanation of (A) correct explanation of (A)

Q36.Better method for preparation of BeF2, among the following is (1) ∆ (2) 𝛥 BeO + C + F2 ⟶BeF2 NH42BeF4 ⟶BeF2 (3) ∆ (4) Δ Be + F2 ⟶BeF2 BeH2 + F2 ⟶BeF2

Q36.Among the following compounds, the one which shows highest dipole moment is (1) (2) (3) (4)

Q36.Enthalpies of formation of CCl4( g), H2O(g), CO2( g) and HCl are −105, −242, −394 and −92 kJ mol−1 respectively. The magnitude of enthalpy of the reaction given below is kJmol−1 . (nearest integer) CCl4( g) + 2H2O(g) →CO2( g) + 4 HCl(g)

Q36.At 600 K, the root mean square (rms) speed of gas X (molar mass = 40) is equal to the most probable speed of gas Y at 90 K. The molar mass of the gas Y is _____ g mol–1 . (Nearest integer)

Q36.Match List-I with List-II. List-I List-II Element detected Reagent used/Product formed A Nitrogen I Na2FeCN5NO B Sulphur II AgNO3 C Phosphorus III Fe4FeCN63 D Halogen IV NH42MoO4 Choose the correct answer from the options given below: (1) A →III; B →I; C →IV; D →II (2) A →II; B →IV; C →I; D → III (3) A →IV; B →II; C →I; D →III (4) A →II; B →I; C →IV; D →III

Q36.Consider the following data Heat of combustion of H2(g) = –241. 8 kJ mol–1 Heat of combustion of C(s) = –393. 5 kJ mol–1 Heat of combustion of C2H5 OH(l)= –1234. 7 kJ mol–1 The heat of formation of C2H5 OH(l) is (–) _____ kJ mol–1 (Nearest integer).

Q36.Given below are two reactions, involved in the commercial production of dihydrogen H2. The two reactions are carried out at temperature “T1” and “T2”, respectively T1 Cs + H2Og ⟶COg + H2g T2 COg + H2Og CatalystCO2g + H2g The temperatures T1 and T2 are correctly related as (1) T1 = T2 (2) T1 < T2 (3) T1 = 100 K, T2 = 1270 K (4) T1 > T2

Q36.Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A : Physical properties of isotopes of hydrogen are different. Reason R : Mass difference between isotopes of hydrogen is very large. In the light of the above statements, choose the correct answer from the options given below: (1) Both A and R are true and R is the correct (2) A is false but R is true explanation of A (3) A is true but R is false (4) Both A and R are true but R is NOT the correct explanation of A

Q36.The volume of HCl, containing 73g L−1 , required to completely neutralise NaOH obtained by reacting 0. 69 g of metallic sodium with water, is _____ mL. (Nearest Integer) (Given : molar Masses of Na, Cl, O, H are 23, 35. 5, 16 and 1g mol−1 respectively)

Q36.The strength of 50 volume solution of hydrogen peroxide is _____ g/L (Nearest integer). Given: Molar mass of H2O2 is 34 g mol−1 Molar volume of gas at STP = 22. 7 L.

Q36.Water decomposes at 2300 K H2O(g) →H2(g) + 12 O2(g) The percent of water decomposing at 2300 K and 1 bar is _____ (Nearest integer). Equilibrium constant for the reaction is 2 × 10−3 at 2300 K

Q36.Match List-I with List-II: List-I List-II A. K I. Thermonuclear reactions B. KCI II. Fertilizer C. KOH III. Sodium potassium pump D. Li IV. Absorbent of CO2 (1) A(III), B(II), C(IV), D(I) (2) A(III), B(IV), C(II), D(I) (3) A(IV), B(I), C(III), D(II) (4) A(IV), B(III), C(I), D(II)

Q36.Increasing order of stability of the resonance structure is: JEE Main 2023 (24 Jan Shift 1) JEE Main Previous Year Paper (1) C, D, B, A (2) C, A, B, D (3) D, C, A, B (4) D, C, B, A

Q37.Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R Assertion A:- The alkali metals and their salts impart characteristic colour to reducing flame. Reason R:- Alkali metals can be detected using flame tests. In the light of the above statements, choose the most appropriate answer form the options given below (1) Both A and R are correct but R is NOT the (2) A is correct but R is not correct. correct explanation of A. (3) A is not correct but R is correct (4) Both A and R are correct and R is the correct explanation of A.