Practice Questions

Q47.If the boiling points of two solvents X and Y (having same molecular weights) are in the ratio 2: 1 and their enthalpy of vaporizations are in the ratio 1 : 2, then the boiling point elevation constant of X is m times the boiling point elevation constant of Y . The value of m is (nearest integer).

Q47.The number of correct statements from the following is........... A. Ecell is an intensive parameter B. A negative Eo means that the redox couple is a stronger reducing agent than the H+/H2 couple. C. The amount of electricity required for oxidation or reduction depends on the stoichiometry of the electrode reaction. D. The amount of chemical reaction which occurs at any electrode during electrolysis by a current is proportional to the quantity of electricity passed through the electrolyte.

Q47.The electrode potential of the following half cell at 298 K X X2+(0. 001M)∥Y2+(0. 01M) Y is _____ ×10−2 V (Nearest integer) Given : E0 = −2. 36 V X2+∣X E0 = +0. 36 V Y2+Y 2.303 RT = 0. 06 V F

Q48. t87.5 is the time required for the reaction to undergo 87. 5% completion and t50 is the time required for the reaction to undergo 50% completion. The relation between t87.5 and t50 for a first order reaction is t87.5 = x × t50 The value of x is _________. (Nearest integer)

Q48.The standard reduction potentials at 295 K for the following half cells are given below: NO3−+ 4H+ + 3e−→NO(g) + 2H2O Eo = 0. 97 V V2+(aq) + 2e−→V(s) Eo = −1. 19 V Fe3+(aq) + 3e−→Fe(s) Eo = −0. 04 V Ag+(aq) + e−→Ag(s) Eo = 0. 80 V Au3+(aq) + 3e−→Au(s) Eo = 1. 40 V The number of metal(s) which will be oxidised by NO3− in aqueous solution is _____.

Q48.The resistivity of a 0. 8M solution of an electrolyte is 5 × 10−3Ωcm. Its molar conductivity is 104Ω−1 cm2 mol−1 . (Nearest integer)

Q48.The number of statement/s which are the characteristics of physisorption is ___________. A. It is highly specific in nature B. Enthalpy of adsorption is high C. It decreases with increase in temperature D. It results into unimolecular layer E. No activation energy is needed

Q48.An organic compound undergoes first order decomposition. If the time taken for the 60% decomposition is 540 s, then the time required for 90% decomposition will be is _____ s. (Nearest integer). Given : ln 10 = 2. 3; log 2 = 0. 3

Q49. A →B The above reaction is of zero order. Half life of this reaction is 50 min . The time taken for the concentration of A to reduce to one-fourth of its initial value is min . (Nearest integer)

Q49.The rate constant for a first order reaction is 20 min−1 . The time required for the initial concentration of the reactant to reduce to its 1 level is ______ × 10−2 min . (Nearest integer) 32

Q49.Total number of acidic oxides among N2O3, NO2, N2O, Cl2 O7, SO2, CO, CaO, Na2 O and NO is _____ .

Q49.The number of correct statements about modern adsorption theory of heterogeneous catalysis from the following is ...... A. The catalyst is diffused over the surface of reactants. B. Reactants are adsorbed on the surface of the catalyst. C. Occurrence of chemical reaction on the catalyst's surface through formation of an intermediate. D. It is a combination of intermediate compound formation theory and the old adsorption theory. E. It explains the action of the catalyst as well as those of catalytic promoters and poisons.

Q49.The reaction 2NO + Br2 →2 NOBr takes place through the mechanism given below NO + Br2 ⇌NOBr2 (fast) NOBr2 + NO →2 NOBr (slow) The overall order of the reaction is _____.

Q49.The graph of log mx vs log p for an adsorption process is a straight line inclined at an angle of 45° with intercept equal to 0. 6020 . The mass of gas adsorbed per unit mass of adsorbent at the pressure of 0. 4 atm is JEE Main 2023 (30 Jan Shift 2) JEE Main Previous Year Paper _____ ×10−1 (Nearest integer) Given : log 2 = 0. 3010

Q50.The number of colloidal systems from the following, which will have 'liquid' as the dispersion medium, is _____. Gem stones, paints, smoke, cheese, milk, hair cream, insecticide sprays, froth, soap lather

Q50.Coagulating value of the electrolytes AlCl3 and NaCl tor As2 S3 are 0. 09 and 50. 04 respectively. The coagulating power of AlCl3 is x times the coagulating power of NaCl. The value of x is

Q50. XeF4 reacts with SbF5 to form [XeFm]n+[SbFy]2− m + n + y + z = ? .

Q51.The density of 3M solution of NaCl is 1 . 0 g mL-1. Molality of the solution is ______ × 10-2 m (Nearest integer). Given: Molar mass of Na and Cl is 23 and 35 . 5 g mol-1 respectively.

Q51.If 5 moles of BaCl2 is mixed with 2 moles of Na3PO4, the maximum number of moles of Ba3PO42formed is _________ (Nearest integer)

Q51.Among following compounds, the number of those present in copper matte is A. CuCO3 B. Cu2 S C. Cu2 O D. FeO

Q51.A solution of sugar is obtained by mixing 200 g of its 25% solution and 500 g of its 40 % solution (both by mass). The mass percentage of the resulting sugar solution is _______ (Nearest integer) JEE Main 2023 (11 Apr Shift 1) JEE Main Previous Year Paper

Q51.The energy of one mole of photons of radiation of frequency 2 × 1012 Hz in Jmol-1 is _____ . (Nearest integer) (Given: h = 6 . 626 × 10-34Js NA = 6 . 022 × 1023 mol-1)

Q51. The electron in the nth orbit of Li2 + is excited to ( n + 1 ) orbit using the radiation of energy 1 . 47 × 10-17 J (as shown in the diagram). The value of n is ___________ Given : RH = 2 . 18 × 10-18 J

Q51.The number of paramagnetic species from the following is [Ni(CN)4]2−, [Ni(CO)4], [NiCl4]2− [Fe(CN)6]4−, [Cu (NH3)4]2+ [Fe(CN)6]3− and [Fe (H2O)6]2+

Q51.On complete combustion, 0 . 492 g of an organic compound gave 0 . 792 g of CO2. The % of carbon in the organic compound is (Nearest integer)