Practice Questions

Q35.But-2-yne is reacted separately with one mole of Hydrogen as shown below: Na Pd / C ← B CH3 - C ≡ C - CH3 →∆ A¯ ¯ liq NH3 +H2 Identify the incorrect statements from the options given below: A. A is more soluble than B. B. The boiling point & melting point of A are higher and lower than B respectively. C. A is more polar than B because dipole moment of A is zero. D. Br2 adds easily to B than A. (1) B and C only (2) B, C and D only (3) A, C and D only (4) A and B only

Q35.One mole of an ideal monoatomic gas is subjected to changes as shown in the graph. The magnitude of the work done (by the system or on the system) is _______ J (nearest integer) Given : log 2 = 0.3, ln 10 = 2.3

Q35.Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R. Assertion A : Isotopes of hydrogen have almost same chemical properties, but difference in their rates of reactions. Reason R: Isotopes of hydrogen have different enthalpy of bond dissociation. In the light of the above statements, choose the most appropriate answer from the options given below: (1) Both A and R are correct but R is NOT the (2) Both A and R are correct and R is the correct correct explanation of A explanation of A (3) A is not correct but R is correct (4) A is correct but R is not correct

Q35.In an ice crystal, each water molecule is hydrogen bonded to _____ neighbouring molecules.

Q35.Arrange the following gases in increasing order of van der Waals constant ′a′ (A) Ar (B) CH4 (C) H2O (D) C6H6 Choose the correct option from the following. (1) D, C, B and A (2) B, C, D and A (3) C, D, B and A (4) A, B, C and D

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.The setting time of Cement is increased by adding (1) Clay (2) Silica (3) Gypsum (4) Limestone

Q36.For a good quality cement, the ratio of silica to alumina is found to be (1) 1. 5 (2) 4. 5 (3) 2 (4) 3

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

Q36.The total number of intensive properties from the following is........... Volume, Molar heat capacity, molarity, Eocell ,Gibbs free energy change, Molar mass, Mole Q37. 4. 5 moles each of hydrogen and iodine is heated in a sealed ten litre vessel.At equilibrium, 3 moles of HI were found. The equilibrium constant for H2(g) + I2(g) ⇌2 HI(g) is ........

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.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.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.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.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. 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.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.Match List I with List II List I List II A. Cobalt catalyst I. (H2 + Cl2) production B. Syngas II. Water gas production C. Nickel catalyst III. Coal gasification D. Brine solution IV. Methanol production Choose the correct answer from the options given below:- JEE Main 2023 (25 Jan Shift 2) JEE Main Previous Year Paper (1) A-IV, B-I, C-II, D-III (2) A-IV, B-III, C-I, D-II (3) A-II, B-III, C-IV, D-I (4) A-IV, B-III, C-II, D-I

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.Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : An aqueous solution of KOH when for volumetric analysis, its concentration should be checked before the use. Reason (R) : On aging, KOH solution absorbs atmospheric CO2 . In the light of the above statements, choose the correct answer from the options given below. (1) (A) is not correct but (R) is correct (2) Both (A) and (R) are correct but (R) is not the correct explanation of (A) (3) Both (A) and (R) are correct and (R) is the (4) (A) is correct but (R) is not correct correct explanation of (A)

Q36.Choose the correct set of reagents for the following conversion transPh - CH = CH - CH3 → cis Ph - CH = CH - CH3 (1) Br2, alc KOH, NaNH2, NaLiqNH3 (2) Br2, alc KOH, NaNH2, H2 Lindlar Catalyst (3) Br2, aqKOH, NaNH2, H2 Lindlar Catalyst (4) Br2, aq KOH, NaNH2, NaLiqNH3

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)