Practice Questions

Q55.Consider the dissociation of the weak acid HX as given below HX(aq) ⇌H+(aq) + X−(aq), Ka = 1.2 × 10−5 [Ka : dissociation constant ] The osmotic pressure of 0.03M aqueous solution of HX at 300 K is _______ ×10−2 bar (nearest integer). [Given : R = 0.083 Lbarmol−1 K−1 ]

Q55.A solution containing 10 g of an electrolyte AB2 in 100 g of water boils at 100.52∘C . The degree of ionization of the electrolyte (α) is _______ ×10−1 . (nearest integer) [Given : Molar mass of AB2 = 200 g mol−1, Kb (molal boiling point elevation const. of water) = 0.52 K kg mol−1 , boiling point of water = 100∘C; AB2 ionises as AB2 →A2+ + 2 B−]

Q55.The values of conductivity of some materials at 298 .15 K in Sm−1 are 2 .1 × 103, 1 .0 × 10−16, 1 .2 × 10, 3 .91 , 1 .5 × 10−2, 1 × 10−7, 1 .0 × 103. The number of conductors among the materials is _____.

Q55. Consider the given reaction. The total number of oxygen atoms present per molecule of the product (P) is _________.

Q55.An artificial cell is made by encapsulating 0.2M glucose solution within a semipermeable membrane. The osmotic pressure developed when the artificial cell is placed within a 0.05M solution of NaCl at 300 K is _______ ×10−1 bar. (nearest integer). [Given : R = 0.083 Lbarmol−1 K−1 ] Assume complete dissociation of NaCl

Q56.The amount of electricity in Coulomb required for the oxidation of 1 mol of H2O to O2 is ______ × 105C .

Q56.Total number of deactivating groups in aromatic electrophilic substitution reaction among the following is JEE Main 2024 (01 Feb Shift 1) JEE Main Previous Year Paper

Q56.For a certain thermochemical reaction M →N at T = 400 K, ΔHo = 77 . 2 kJ mol-1, ΔSo = 122JK-1, log equilibrium constant ( logK ) is - _____ × 10-1.

Q56.A solution of H2 SO4 is 31. 4% H2 SO4 by mass and has a density of 1. 25 g/ mL. The molarity of the H2 SO4 solution is M (nearest integer) [Given molar mass of H2 SO4 = 98 g mol−1 ]

Q56.Among the given organic compounds, the total number of aromatic compounds is JEE Main 2024 (27 Jan Shift 1) JEE Main Previous Year Paper Q57. 3−Methylhex-2-ene on reaction with HBr in presence of peroxide forms an addition product (A). The number of possible stereoisomers for ' A ' is ________.

Q56.The vapour pressure of pure benzene and methyl benzene at 27∘C is given as 80 Torr and 24 Torr, respectively. The mole fraction of methyl benzene in vapour phase, in equilibrium with an equimolar mixture of those two liquids (ideal solution) at the same temperature is _______ ×10−2 (nearest integer)

Q56.Consider the following reaction, the rate expression of which is given below A + B →C rate = k[A]1/2[ B]1/2 The reaction is initiated by taking 1M concentration of A and B each. If the rate constant (k) is 4.6 × 10−2 s−1 , then the time taken for A to become 0.1M is ______ sec. (nearest integer)

Q56.The standard reduction potentials at 298 K for the following half cells are given below : Cr2O2−7 + 14H+ + 6e−→2Cr3+ + 7H2O, E∘= 1.33 V Fe3+(aq) + 3e−→Fe E∘= −0.04 V Ni2+(aq) + 2e−→Ni E∘= −0.25 V Consider the given electrochemical reactions, The Ag+(aq) + e−→Ag E∘= 0.80 V Au3+(aq) + 3e−→Au E∘= 1.40 V number of metal(s) which will be oxidized be Cr2O2−7 , in aqueous solution is ______

Q56.A solution is prepared by adding 1 mole ethyl alcohol in 9 mole water. The mass percent of solute in the solution is ________ (Integer answer) (Given : Molar mass in gmol−1 Ethyl alcohol : 46 water: 18)

Q56.Consider the following reaction A + B →C The time taken for A to become 1/4th of its initial concentration is twice the time taken to become 1/2 of the same. Also, when the change of concentration of B is plotted against time, the resulting graph gives a straight JEE Main 2024 (08 Apr Shift 1) JEE Main Previous Year Paper line with a negative slope and a positive intercept on the concentration axis. The overall order of the reaction is _______

Q56.During Kinetic study of reaction 2A + B →C + D , the following results were obtained : A [M] B [M] initial rate of formation of D I 0.1 0.1 6.0 × 10−3 II 0.3 0.2 7.20 × 10−2 Based on above data, overall order of the reaction is III 0.3 0.4 2.88 × 10−1 IV 0.4 0.1 2.40 × 10−2 ______

Q56.Among VO+2 , MnO−4 and Cr2O2−7 , the spin-only magnetic moment value of the species with least oxidising ability is ______ BM (Nearest integer). (Given atomic member V = 23, Mn = 25, Cr = 24) JEE Main 2024 (06 Apr Shift 2) JEE Main Previous Year Paper

Q56.r = kA for a reaction, 50% of A is decomposed in 120 minutes. The time taken for 90% decomposition of A is ______ minutes.

Q56.Consider the following single step reaction in gas phase at constant temperature. 2 A(g) + B(g) →C(g) The initial rate of the reaction is recorded as r1 when the reaction starts with 1.5 atm pressure of A and 0.7 atm pressure of B . After some time, the rate r2 is recorded when the pressure of C becomes 0.5 atm. The ratio r1 : r2 is ______ ×10−1 . (Nearest integer) JEE Main 2024 (05 Apr Shift 2) JEE Main Previous Year Paper

Q56.One Faraday of electricity liberates x × 10 – 1 gram atom of copper from copper sulphate, x is______.

Q56.NO2 required for a reaction is produced by decomposition of N2O5 in CCl4 as by equation 2N2O5 ( g ) →4NO2 ( g ) + O2 ( g ) The initial concentration of N2O5 is 3 mol L-1 and it is 2 . 75 mol L-1 after 30 minutes. The rate of formation of NO2 is x × 10-3 mol L-1 min-1, value of x is ________.

Q56.Time required for 99.9% completion of a first order reaction is _______ times the time required for completion of 90% reaction.(nearest integer)

Q56.If 50 mL of 0. 5M oxalic acid is required to neutralise 25 mL of NaOH solution, the amount of NaOH in 50 mL of given NaOH solution is_______g. JEE Main 2024 (29 Jan Shift 2) JEE Main Previous Year Paper

Q57.The 'Spin only’ Magnetic moment for [Ni ( NH3 ) 6] 2 + is______ × 10 – 1 BM. (given = Atomic number of Ni : 28) Round off your answer to the nearest integer.

Q57.The fusion of chromite ore with sodium carbonate in the presence of air leads to the formation of products A and B along with the evolution of CO2 . The sum of spin-only magnetic moment values of A and B is ______ B.M. (Nearest integer) [Given atomic number : C : 6, Na : 11, O : 8, Fe : 26, Cr : 24]