Practice Questions

Q46.A solution of sodium sulphate contains 92 𝑔 of Na+ ions per kilogram of water. The molality of Na+ ions in that solution in mol kg-1 is: (1) 16 (2) 4 (3) 12 (4) 8

Q46.The correct set of species responsible for the photochemical smog is: (1) CO2, NO2, SO2 and hydrocarbons (2) NO2, O2, O3 and hydrocarbons (3) NO2, NO2 and hydrocarbons (4) NO, NO2, O3 and hydrocarbons

Q46.Calculate the standard cell potential (in V) of the cell in which the following reaction takes place: Fe2 + aq + Ag+aq →Fe3 + aq + Ag(s) Given that EAg+o / Ag = x V = y V EFe2o + / Fe = z V EFe3o + / Fe JEE Main 2019 (08 Apr Shift 2) JEE Main Previous Year Paper (1) x + 2y - 3z (2) x - y (3) x - z (4) x + y - z

Q46.The noble gas that does not occur in the atmosphere is; (1) Kr (2) Ne (3) Ra (4) He Q47.1 g of a non-volatile non-electrolyte solute is dissolved in 100 g of two different solvents A and B whose ∆TbA ebullioscopic constants are in the ratio of 1: 5. The ratio of the elevation in their boiling points, ∆TbB, is: (assuming they have the same molar mass) (1) 10: 1 (2) 1: 5 (3) 1: 0.2 (4) 5: 1

Q46.Element B forms ccp structure and A occupies half of the octahedral voids, while oxygen atoms occupy all the tetrahedral voids. The structure of bimetallic oxide is: (1) A2BO4 (2) AB2O4 (3) A2B2O (4) A4B2O JEE Main 2019 (08 Apr Shift 1) JEE Main Previous Year Paper

Q46.The standard Gibbs energy for the given cell reaction in kJ mol−1 at 298 K is: Zn(s) + Cu2+(aq) ⟶Zn2+(aq) + Cu(s) , E0 = 2 V at 298 K (Faraday's constant , F = 96000 C mol−1) (1) −192 (2) 192 (3) 384 (4) −384

Q46.A solution is prepared by dissolving 0.6 g of urea (molar mass = 60 g mol−1 ) and 1.8 g of glucose (molar mass = 180 g mol−1 ) in 100 mL of water at 27oC. The osmotic pressure of the solution is: ( R = 0.08206 Latm K−1 mol−1 ) (1) 8.2 atm (2) 2.46 atm (3) 4.92 atm (4) 1.64 atm

Q46.A bacterial infection in an internal wound grows as N'(t) = N0exp(t) , where the time t is in hours. A dose of antibiotic, taken orally, needs 1 hour to reach the wound. Once it reaches there, the bacterial population goes down as dN dt = −5N2 . What will be the plot of N0N vs t after 1 hour? JEE Main 2019 (10 Apr Shift 1) JEE Main Previous Year Paper (1) (2) (3) (4)

Q46.The haemoglobin and the gold sol are examples of (1) positively charged sols, (2) negatively and positively charged sols, respectively. (3) negatively charged sols. (4) positively and negatively charged sols, respectively.

Q46.Given the equilibrium constant: KC of the reaction: Cu(s) + 2Ag+(aq) →Cu2+(aq) + 2Ag(s) is 10 × 1015 calculate the E cell 0 of this reaction at 298 K [2.303 RTF at 298 K = 0.059 V] (1) 0.04736mV (2) 0.4736mV (3) 0.4736 V (4) 0.04736 V JEE Main 2019 (11 Jan Shift 2) JEE Main Previous Year Paper

Q46.The freezing point of a 4% aqueous solution of X is equal to the freezing point of a 12% aqueous solution of Y . If the molecular weight of X is A , then the molecular weight of Y will be (1) 2A (2) A (3) 4A (4) 3A

Q46.The freezing point of a diluted milk sample is found to be −0.2∘C, while it should have been −0.5∘C for pure milk. How much water has been added to pure milk to make the diluted sample? (1) 1 cup of water to 2 cups of pure milk (2) 3 cups of water to 2 cups of pure milk (3) 1 cup of water to 3 cups of pure milk (4) 2 cups of water to 3 cups of pure milk

Q46.Which primitive unit cell has unequal edge lengths (a ≠b ≠c) and all axial angles different from 90o (1) Hexagonal (2) Monoclinic (3) Triclinic (4) Tetragonal

Q46.Assertion: For the extraction of iron, haematite ore is used. Reason: Haematite is a carbonate ore of iron. (1) Only the assertion is correct. (2) Only the reason is correct. (3) Both the assertion and reason are correct and the (4) Both the assertion and reason are correct, but the reason is the correct explanation for the assertion. reason is not the correct explanation for the assertion.

Q47.The correct match between Item I and Item II is: Item I Item II (A) Benzaldehyde (P) Mobile phase (B) Alumina (Q) Adsorbent (C) Acetonitrile (R) Adsorbate (1) (A) →(P); (B) →(R); (C) →(Q) (2) (A) →(R); (B) →(Q); (C) →(P) (3) (A) →(Q); (B) →(P); (C) →(R) (4) (A) →(Q); (B) →(R); (C) →(P)

Q47.The given plots represent the variation of the concentration of a reactant R with time for two different reactions (i) and (ii) . The respective orders of the reaction are (i) (ii) (1) 1,1 (2) 0,1 (3) 1,0 (4) 0,2

Q47.Liquids A and B form an ideal solution in the entire composition range. At 350K, the vapour pressure of pure A and pure B are 7 × 103 Pa and 12 × 103 Pa , respectively. The composition of the vapour in equilibrium with a solution containing 40 mole percent of A at this temperature is: (1) xA = 0.4; xB = 0.6 (2) xA = 0.76; xB = 0.24 (3) xA = 0.28; xB = 0.72 (4) xA = 0.37; xB = 0.63

Q47. HF has highest boiling point among hydrogen halides, because it has: (1) lowest dissociation enthalpy (2) strongest van der Waals’ interactions (3) strongest hydrogen bonding (4) lowest ionic character

Q47.An element has a face-centered cubic fcc structure with a cell edge of a. The distance between the centres of two nearest tetrahedral voids in the lattice is a 3 (1) (2) 2 2a (3) a (4) √2a

Q47.The electrolytes usually used in the electroplating of gold and silver, respectively, are: (1) [Au (NH3)2]+ and [Ag (CN)2]− (2) [Au (CN)2]− and [AgCl2]− (3) [Au (OH)4]− and [Ag (OH)2]− (4) [Au (CN)2]− and [Ag (CN)2]−

Q47.The reaction 2X →B is a zeroth order reaction. If the initial concentration of X is 0.2M, the half-life is 6 h. When the initial concentration of X is 0.5M, the time required to reach its final concentration of 0.2M will be (1) 9.0 h (2) 12.0 h (3) 18.0 h (4) 7.2 h

Q47.Which one of the following statements regarding Henry's law is not correct? (1) Different gases have different 𝐾𝐻 (Henry's law (2) The partial pressure of the gas in vapour phase is constant) values at the same temperature proportional to the mole fraction of the gas in the solution (3) Higher the value of 𝐾𝐻 at a given pressure, (4) The value of 𝐾𝐻 increases with increase of higher is the solubility of the gas in the liquids temperature and 𝐾𝐻 is function of the nature of the gas

Q47.For the cell Zn(s) Zn2+(aq)∥Mx+(aq) M(s), different half cells and their standard electrode potentials are given below: JEE Main 2019 (11 Jan Shift 1) JEE Main Previous Year Paper If E∘ = −0.76 V, which cathode will give a maximum value of E cell0 per electron transferred? Zn2+/Zn (1) Ag+/Ag (2) Fe3+/Fe2+ (3) Au3+/Au (4) Fe2+/Fe

Q47.The standard electrode potential Eo and its temperature coefficient ( dTdE ) for a cell are 2 V and −5×10−4 V K−1 at 300 K, respectively. The reaction is Zn (s) + Cu2+ (aq) →Zn2+ (aq) + Cu (s). The standard reaction enthalpy (ΔrH−) at 300 K in mol−1 is [Use R = 8 J K−1 mol−1 and F =96,500 C mol−1] (1) −412.8 (2) 206.4 (3) −384.0 (4) 192.0

Q47.A gas undergoes physical adsorption on a surface and follows the given Freundlich adsorption isotherm equation x = kp0.5 m Adsorption of the gas increases with: (1) Decrease in p and increase in T (2) Increase in p and decrease in T (3) Increase in p and increase in T (4) Decrease in p and decrease in T