Practice Questions

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.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)

Q53.A certain orbital has n = 4 and ml = −3. The number of radial nodes in this orbital is _______. (Round off to the Nearest Integer).

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)

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.At 298 K, the enthalpy of fusion of a solid X is 2 . 8 kJ mol-1 and the enthalpy of vaporisation of the liquid X is 98 . 2 kJ mol-1. The enthalpy of sublimation of the substance X in kJ mol-1 is ______. (in nearest integer)

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.Among the following, number of metal/s which can be used as electrodes in the photoelectric cell is ___ . (Integer answer) JEE Main 2021 (25 Feb Shift 2) JEE Main Previous Year Paper (A) Li (B) Na (C) Rb (D) Cs

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 OH− concentration in a mixture of 5. 0 mL of 0. 0504 M NH4 Cl and 2 mL of 0. 0210 M NH3 solution is x × 10−6 M . The value of x is (Nearest integer) [Given Kw = 1 × 10−14 and Kb = 1. 8 × 10−5]

Q54.Assuming ideal behaviour, the magnitude of log K for the following reaction at 25°C is x × 10−1. The value of x is __________. (Integer answer) 3HC ≡CH(g) ⇌C6H6(l) [Given: ΔfG°(HC ≡CH) = −2. 04 × 105 J mol−1; ΔfG°(C6H6) = −1. 24 × 105 J mol−1; R = 8. 314 J K−1 mol−1 ]

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.A system does 200 J of work and at the same time absorbs 150 J of heat. The magnitude of the change in internal energy is ______ J. (Nearest integer)

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.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.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.Value of KP for the equilibrium reaction N2O4( g) ⇌2 NO2( g) at 288 K is 47. 9. The KC for this reaction at same temperature is (Nearest integer) (R = 0. 083 L bar K−1 mol−1)

Q54.An empty LPG cylinder weighs 14 . 8 kg. When full, it weighs 29 . 0 kg and shows a pressure of 3 . 47 atm . In the course of use at ambient temperature, the mass of the cylinder is reduced to 23 . 0 kg . The final pressure inside the cylinder is _____ atm. (Nearest integer) (Assume LPG to be an ideal gas) JEE Main 2021 (01 Sep Shift 2) JEE Main Previous Year Paper

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.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]

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