Practice Questions

Q54.The vapour pressure of 30% (w/v), aqueous solution of glucose is ________ mm Hg at 25∘C . JEE Main 2023 (15 Apr Shift 1) JEE Main Previous Year Paper [Given: The density of 30% (w/v), aqueous solution of glucose is 1. 2 g cm–3 and vapour pressure of pure water is 24 mm Hg.] (Molar mass of glucose is 180 g mol–1 )

Q54.See the following chemical reaction: Cr2O72 - + XH+ + 6Fe2 + →YCr3 + + 6Fe3 + + ZH2O The sum of X, Y and Z is

Q54.The sum of bridging carbonyls in W(CO)6 and Mn2 (CO)10 is _____ .

Q54.(i) X(g) ⇌Y(g) + Z(g) Kp1 = 3 (ii) A(g) ⇌2 B( g) Kp2 = 1 If the degree of dissociation and initial concentration of both the reactants X ( g ) and A ( g ) are equal, then 𝑝1 the ratio of the total pressure at equilibrium is equal to x: 1. The value of x is (Nearest integer) 𝑝2

Q54.Uracil is base present in RNA with the following structure. % of N in uracil is _______.

Q54. The number of hyperconjugation structures involved to stabilize carbocation formed in the above reaction is __________.

Q54.A ( g ) ⇌2 B ( g ) + C ( g ) For the given reaction, if the initial pressure is 450 mmHg and the pressure at time t is720 mmHg at a constant temperatureT and constant volume V. The fraction of A ( g ) decomposed under these conditions is x × 10-1. The value of x is (nearest integer)

Q54.The value of log K for the reaction A ⇌B at 298 K is _______ . (Nearest integer) Given: 𝛥H° = - 54 . 07 kJ mol-1 𝛥S° = 10JK-1 mol-1 (Taken 2 . 303 × 8 . 314 × 298 = 5705 )

Q55.If the formula of Borax is Na2 B4O𝑥( OH ) 𝑦· zH2O, then x + y + z = ______ Q56.0 . 400 g of an organic compound ( X ) gave 0 . 376 g of AgBr in Carius method for estimation of bromine. % of bromine in the compound ( 𝑋) is (Given: Molar mass AgBr = 188 g mol-1 Br = 80 g mol-1

Q55.When Fe0 . 93O is heated in presence of oxygen, it converts to Fe2O3. The number of correct statement/s from the following is ______ . A. The equivalent weight of Fe0 . 93O is Molecular0 . 79weight B. The number of moles of Fe2 + and Fe3 + in 1 mole of Fe0 . 93O is 0 . 79 and 0 . 14 respectively. C. Fe0 . 93O is metal deficient with lattice comprising of cubic closed packed arrangement of O2 - ions. D. The % composition of Fe2 + and Fe3 + in Fe0 . 93O is 85% and 15% respectively. Q56.5 g of NaOH was dissolved in deionized water to prepare a 450 mL stock solution. What volume (in mL) of this solution would be required to prepare 500 mL of 0 . 1 M solution ? Given : Molar Mass of Na, O and H is 23, 16 and 1 g mol – 1 respectively

Q55.A solution containing 2 g of a non-volatile solute in 20 g of water boils at 373 . 52 K. The molecular mass of the solute is _____ gmol-1. (Nearest integer) Given, water boils at 373 K, Kb for water = 0 . 52K kg mol-1

Q55.The total pressure of a mixture of non-reacting gases X ( 0 . 6 g ) and Y ( 0 . 45 g ) in a vessel is 740 mm of Hg. The partial pressure of the gas X is mm of Hg . (Nearest Integer) (Given : molar mass X = 20 and Y = 45 g mol-1 )

Q55.The number of endothermic process/es from the following is _______. A. I2 ( g ) →2I ( g ) B. HCl ( g ) →H ( g ) + Cl ( g ) C. H2O ( l ) →H2O ( g ) D. C ( s ) + O2 ( g ) →CO2 ( g ) E. Dissolution of ammonium chloride in water

Q55.The spin only magnetic moment of [Mn (H2O)6]2+ complexes is B. M. (Nearest integer) (Given atomic number of Mn = 25) JEE Main 2023 (01 Feb Shift 2) JEE Main Previous Year Paper

Q55.Consider the graph of Gibbs free energy G vs extent of reaction. The number of statement/s from the following which are true with respect to points (a), (b) and (c) is ______ A. Reaction is spontaneous at (a) and (b) B. Reaction is at equilibrium at point (b) and non-spontaneous at point (c) C. Reaction is spontaneous at (a) and non-spontaneous at (c) D. Reaction is non-spontaneous at (a) and (b)

Q55.The number of correct statements from the following is ___________ (A) Conductivity always decreases with decrease in concentration for both strong and weak electrolytes. (B) The number of ions per unit volume that carry current in a solution increases on dilution. (C) Molar conductivity increases with decrease in concentration. (D) The variation in molar conductivity is different for strong and weak electrolytes. (E) For weak electrolytes, the change in molar conductivity with dilution is due to decrease in degree of dissociation.

Q55.An atomic substance A of molar mass 12 g mol – 1 has a cubic crystal structure with edge length of 300 pm. The no. of atoms present in one unit cell of A is (Nearest integer) Given the density of A is 3 . 0 g m m-1 and NAA = 6 . 02 × 1023 mol-1 Q56.0 . 004 M K2SO4 solution is isotonic with 0 . 01 M glucose solution. Percentage dissociation of K2SO4 is _____ (Nearest integer) = m Volt and

Q55.The total number of chiral compound/s from the following is Q56.25 mL of an aqueous solution of KCl was found to require 20 mL of 1M AgNO3 solution when titrated using K2CrO4 as an indicator. What is the depression in freezing point of KCl solution of the given concentration? (Nearest integer). (Given : Kf = 2 . 0 K kg mol-1 ) Assume 1) 100% ionization and 2) density of the aqueous solution as 1 g mL-1

Q55.The Cl −Co −Cl bond angle values in a fac- [Co (NH3)3 Cl3] complex is/are: (1) 90° & 180° (2) 90° (3) 180° (4) 90° & 120° JEE Main 2023 (30 Jan Shift 2) JEE Main Previous Year Paper

Q55.The sum of oxidation state of the metals in Fe(CO)5 , VO2+ and WO3 is

Q55.The number of incorrect statement/s about the black body from the following is______ (A) Emit or absorb energy in the form of electromagnetic radiation. (B) Frequency distribution of the emitted radiation depends on temperature. (C) At a given temperature, intensity vs frequency curve passes through a maximum value. JEE Main 2023 (10 Apr Shift 1) JEE Main Previous Year Paper (D) The maximum of the intensity vs frequency curve is at a higher frequency at higher temperature compared to that at lower temperature.

Q56.At 27°C, a solution containing 2 . 5 g of solute in 250 . 0 mL of solution exerts an osmotic pressure of 400 Pa. The molar mass of the solute is g mol-1 (Nearest integer) (Given : R = 0 . 083 L bar -1 mol-1 )

Q56. The number of molecules which gives haloform test among the following molecules is :

Q56.In alkaline medium, the reduction of permanganate anion involves a gain of ____________ electrons.

Q56.For a reversible reaction A ⇌B, the ΔH forward reaction = 20 kJ mol–1 . The activation energy of the uncatalyzed forward reaction is 300 kJ mol–1 . When the reaction is catalysed keeping the reactant concentration same, the rate of the catalysed forward reaction at 27∘C is found to be same as that of the uncatalyzed reaction at 327∘C. The activation energy of the catalysed backward reaction is _______ kJ mol–1 . Q57. 20 mL of 0. 5 M NaCl is required to coagulate 200 mL of As2 S3 solution in 2 hours. The coagulating value of NaCl is ___________.