Practice Questions

Q53.The equilibrium constant Kc at 298 K for the reaction A + B ⇌C + D is 100 . Starting with an equimolar solution with concentrations of A, B, C and D all equal to 1M, the equilibrium concentration of D is _____ ×10−2M. (Nearest integer)

Q53.The average S −F bond energy in kJ mol−1 of SF6 is _. (Rounded off to the nearest integer) [Given : The values of standard enthalpy of formation of SF6(g), S(g) and F(g) are −1100, 275 and 80 kJ mol−1 respectively.]

Q53.The pH of a solution obtained by mixing 50 mL of 1 M HCl and 30 mL of 1 M NaOH is x × 10-4 . The value of x is (Nearest integer) log 2 . 5 = 0 . 3979

Q53.The gas phase reaction 2 A(g) ⇌A2(g) at 400 K has ΔGo = +25. 2 kJ mol−1 . The equilibrium constant KC for this reaction is ___ ×10−2 . (Round off to the Nearest integer) Use : R = 8. 3 J mol−1 K−1, ln 10 = 2. 3 log10 2 = 0. 30, 1 atm = 1 bar antilog (−0. 3) = 0. 501

Q53.A home owner uses 4 . 00 × 103 m3 of methane CH4 gas, (assume CH4 is an ideal gas) in a year to heat his home. Under the pressure of 1 . 0 atm and 300 K, mass of gas used is x × 105 g. The value of x is ______. (Nearest integer) (Given R = 0 . 083 L atm K-1 mol-1)

Q53.At 25°C, 50 g of iron reacts with HCl to form FeCl2 . The evolved hydrogen gas expands against a constant pressure of 1 bar. The work done by the gas during this expansion is -_______ J. (Round off to the Nearest Integer) [Given : R = 8. 314 J mol−1 K−1 . Assume, hydrogen is an ideal gas] JEE Main 2021 (16 Mar Shift 2) JEE Main Previous Year Paper [Atomic mass off Fe is 55. 85 u ]

Q53.For the reaction A𝑔→Bg, the value of the equilibrium constant at 300 K and 1 atm is equal to 100 . 0 . The value of ΔGo for the reaction at 300 K and 1 atm in Jmol-1 is -𝑥R, where x is (Rounded off to the nearest integer) R = 8 . 31 J mol-1 K-1 and ln10 = 2 . 3

Q53.The number of species having non-pyramidal shape among the following is: (A) SO3 (B) NO−3 (C) PCl3 (D) CO2−3

Q53.An average person needs about 10000 kJ energy per day. The amount of glucose (molar mass = 180. 0 g mol−1 ) needed to meet this energy requirement is ______ g. (Use : ΔCH (glucose) = −2700 kJ mol−1 ) Q54. 2 SO2( g) + O2( g) ⇌2 SO3( g) In an equilibrium mixture, the partial pressures are PSO3 = 43 kPa; PO2 = 530 Pa and PSO2 = 45 kPa. The equilibrium constant KP = _____ × 10−2. (Nearest integer) Q55. 250 mL of 0. 5M NaOH was added to 500 mL of 1M HCl. The number of unreacted HCl molecules in the solution after the complete reaction is p ×1021 . Find out p (Nearest integer) (NA = 6. 022 × 1023)

Q54.The number of hydrogen bonded water molecule(s) associated with stoichiometry CuSO4 ⋅5H2O is __________ .

Q54.For water at 100°C and 1 bar, Δvap H −Δvap U =¯× 102 J mol−1 (Round off to the Nearest Integer) [Use : R = 8. 31 J mol−1 K−1] [Assume volume of H2O(l) is much smaller than volume of H2O(g). Assume H2O(g) treated as an ideal gas]

Q54.Two flasks I and II shown below are connected by a valve of negligible volume. When the valve is opened, the final pressure of the system in bar is x × 10−2 . The value of x is (Integer answer) [Assume : Ideal gas; 1 bar = 105 Pa : Molar mass of N2 = 28. 0 mol−1; R = 8. 31 J mol−1 K−1]

Q54.A homogeneous ideal gaseous reaction AB2(g) ⇌A(g) + 2 B(g) is carried out in a 25 litre flask at 27°C . The initial amount of AB2 was 1 mole and the equilibrium pressure was 1. 9 atm . The value of Kp is x × 10−2 . The value of x is (Integer answer) [R = 0. 08206 dm3 atm K−1 mol−1]

Q54.The pressure exerted by a non-reactive gaseous mixture of 6. 4 g of methane and 8. 8 g of carbon dioxide in a 10 L vessel at 27°C is _____ kPa. (Round off to the Nearest Integer). [Assume gases are ideal, R = 8. 314 J mol−1 K−1 Atomic masses: C : 12. 0 u, H : 1. 0 u, O : 16. 0 u ]

Q54.Sulphurous acid (H2 SO3) has Ka1 = 1. 7 × 10−2 and Ka2 = 6. 4 × 10−8. The pH of 0. 588 M H2 SO3 is____________ (Round off to the Nearest Integer ).

Q54.The stepwise formation of CuNH34 2 + is given below: K1 Cu2 + + NH3 ⇌CuNH3 2 + K2 CuNH3 2 + + NH3 ⇌CuNH32 2 + K3 CuNH32 2 + + NH3 ⇌CuNH33 2 + K4 CuNH33 2 + + NH3 ⇌CuNH34 2 + The value of stability constants K1, K2, K3 and K4 are 104, 1 . 58 × 103, 5 × 102 and 102 respectively. The overall equilibrium constants for dissociation of CuNH34 2 + is 𝑥× 10-12 . The value of x is _____ (Rounded off to the nearest integer)

Q54.The solubility of CdSO4 in water is 8. 0 × 10−4 mol L−1 . Its solubility in 0. 01M H2 SO4 solution is ___ ×10−6 mol L−1 (Round off to the Nearest integer) (Assume that solubility is much less than 0. 01 M ) Q55. 10. 0 ml of Na2 CO3 solution is titrated against 0. 2 M HCl solution. The following values were obtained in 5 readings. 4. 8 ml, 4. 9 ml, 5. 0 ml, 5. 0 ml and 5. 0 ml JEE Main 2021 (18 Mar Shift 2) JEE Main Previous Year Paper Based on these readings, and convention of titrimetric estimation of concentration of Na2 CO3 solution is ___ mM. (Round off to the Nearest integer)

Q54.The pH of ammonium phosphate solution, if pka of phosphoric acid and pkb of ammonium hydroxide are 5. 23 and 4. 75 respectively, is

Q54.The transformation occurring in Duma's method is given below y y z y C2H7 N + 2x + 2CuO →xCO2 + 2H2O + 2 N2 + 2x + 2Cu The value of y is (Integer answer)

Q54.When 0. 15 g of an organic compound was analyzed using Carius method for estimation of bromine, 0. 2397 g of AgBr was obtained. The percentage of bromine in the organic compound is _________.(Nearest integer) [Atomic mass : Silver = 108, Bromine = 80]

Q54.In the sulphur estimation, 0. 471 g of an organic compound gave 1. 44 g of barium sulfate. The percentage of sulphur in the compound is. (Nearest integer) (Atomic Mass of Ba = 137u )

Q54.For the reaction A(g) ⇌B(g) at 495 K, ΔrG° = −9. 478 kJ mol−1 If we start the reaction in a closed container at 495 K with 22 millimoles of A , the amount of B is the equilibrium mixture is ________ millimoles. (Round off to the Nearest Integer). [R = 8. 314 J mol−1 K−1; ℓn10 = 2. 303] JEE Main 2021 (16 Mar Shift 1) JEE Main Previous Year Paper

Q54.The equilibrium constant for the reaction A(s) ⇌M(s) + 12 O2( g) is Kp = 4. At equilibrium, the partial pressure of O2 is _____ atm. (Round off to the nearest integer) Q55. 10. 0 mL of 0. 05 M KMnO4 solution was consumed in a titration with 10. 0 mL of given oxalic acid dihydrate solution. The strength of given oxalic acid solution is ........ ×10−2 g/L . (Round off to the nearest integer)

Q54.The total number of C −C sigma bond/s in mesityl oxide (C6H10O) is (Round off to the Nearest Integer).

Q54.For the reaction C2H6 →C2H4 + H2 the reaction enthalpy ΔrH in kJmol−1 is (Round off to the Nearest Integer). [Given : Bond enthalpies in kJmol−1 : C −C : 347, C = C : 611; C −H : 414, H −H : 436]