Practice Questions

Q38.Which one of the following alkaline earth metal sulphates has its hydration enthalpy greater than its lattice enthalpy? (1) SrSO4 (2) CaSO4 (3) BeSO4 (4) BaSO4 JEE Main 2015 (04 Apr) JEE Main Previous Year Paper

Q38.The increase of pressure on ice ⇌water system at constant temperature will lead to: (1) A decrease in the entropy of the system (2) An increase in the Gibbs energy of the system (3) A shift of the equilibrium in the forward direction(4) No effect on the equilibrium

Q39.In Carius method of estimation of halogens, 250 mg of an organic compound gave 141 mg AgBr. What is the percentage of bromine in the compound (atomic mass of Ag = 108 and atomic number of Br = 80 )? (1) 60 (2) 24 (3) 36 (4) 48

Q39.Permanent hardness in water cannot be cured by: (1) Treatment with washing soda (2) Ion exchange method (3) Calgon's method (4) Boiling

Q39.Which physical property of di-hydrogen is wrong? (1) Tasteless gas (2) Odourless gas (3) Colourless gas (4) Non-inflammable gas

Q40.The correct order of thermal stability of hydroxides is (1) Mg(OH)2 < Sr(OH)2 < Ca(OH)2 < Ba(OH)2 (2) Mg(OH)2 < Ca(OH)2 < Sr(OH)2 < Ba(OH)2 (3) Ba(OH)2 < Sr(OH)2 < Ca(OH)2 < Mg(OH)2 (4) Ba(OH)2 < Ca(OH)2 < Sr(OH)2 < Mg(OH)2 JEE Main 2015 (10 Apr Online) JEE Main Previous Year Paper Q41.1.4 g of an organic compound was digested according to Kjeldahl's method and the ammonia evolved was absorbed in 60 mL of M/10 H2SO4 solution. The excess sulphuric acid required 20 mL of M/10 NaOH solution for neutralization. The percentage of nitrogen in the compound is: (1) 24 (2) 3 (3) 5 (4) 10

Q40.Which of the alkaline earth metal halides given below is essentially covalent in nature? (1) BeCl2 (2) MgCl2 (3) SrCl2 (4) CaCl2

Q40.Which of the following compounds will exhibit geometrical isomerism? (1) 1, 1 - Diphenyl - 1 - propane (2) 1 - Phenyl - 2 - butene (3) 3 - Phenyl - 1 - butene (4) 2 - Phenyl - 1 - butene

Q41.The number of structural isomers for C6H14 is: (1) 4 (2) 5 (3) 6 (4) 3

Q41.Assertion: Nitrogen and Oxygen are the main components in the atmosphere but these do not react to form oxides of nitrogen. Reason: The reaction between nitrogen and oxygen requires high temperature. (1) Both the Assertion and Reason are incorrect. (2) Both Assertion and Reason are correct and the Reason is the correct explanation for the Assertion. (3) Both Assertion and Reason are correct, but the (4) The Assertion is incorrect but the Reason is Reason is not the correct explanation for the correct. Assertion.

Q42.Sodium metal crystallizes in a body centred cubic lattice with a unit cell edge of 4.29 Å . The radius of sodium atom is approximately: (1) 0.93 Å (2) 1.86 Å (3) 3.22 Å (4) 5.72 Å

Q42.Match the organic compounds in column - I with the Lassaigne's test result in column - II appropriately: Column – I Column - II A. Aniline i. Red colour with FeCl3 B. Benzene sulfonic acid ii. Violet color with sodium nitroprusside C. Thiourea iii. Blue color with and acidic solution of FeSO4 (1) A - ii ; B - iii ; C - i (2) A - iii ; B - ii ; C - i (3) A - ii ; B - i ; C - iii (4) A - iii ; B - i ; C - ii

Q42.The optically inactive compound from the following is: (1) 2-chloropropanal (2) 2-chloro-2-methylbutane (3) 2-chlorobutane (4) 2-chloropentane

Q43.Which of the following pairs of compounds are positional isomers? JEE Main 2015 (11 Apr Online) JEE Main Previous Year Paper (1) (2) (3) (4)

Q43.A compound A with molecular formula C10H13Cl, gives a white precipitate on adding silver nitrate solution. A on reacting with alcoholic KOH gives compound B as the main product. B on ozonolysis, gives C and D. C gives Cannizaro reaction, but not aldol condensation. D gives aldol condensation, but not Cannizaro reaction. A is (1) (2) (3) (4)

Q43.The vapour pressure of acetone at 20oC is 185 torr. When 1. 2 g of a non-volatile substance was dissolved in 100 g of acetone at 20oC , its vapour pressure was 183 torr. The molar mass (g mol−1) of the substance is: (1) 488 (2) 32 (3) 64 (4) 128

Q44.Addition of phosphate fertilizers to water bodies causes: (1) Deposition of calcium phosphate (2) Enhanced growth of algae (3) Increase in fish population (4) Increase in amount of dissolved oxygen in water

Q44.Photochemical smog consists of excessive amount of X, in addition to aldehydes, ketones, peroxy acetyl nitrile (PAN). X is: (1) CH4 (2) CO2 (3) O3 (4) CO

Q44.Two Faraday of electricity is passed through a solution of CuSO4 . The mass of copper deposited at the cathode is: (Atomic mass of Cu = 63.5 amu) (1) 127 g (2) 0 g (3) 63.5 g (4) 2 g

Q45.Higher order (>3) reactions are rare due to: (1) Loss of active species on collision. (2) Low probability of simultaneous collision of all the reacting species. (3) Increase in entropy and activation energy as more (4) Shifting of equilibrium towards reactants due to molecules are involved. elastic collisions. Q46. 3 g of activated charcoal was added to 50 mL of acetic acid solution (0. 06 N) in a flask. After an hour, it was filtered and the strength of the filtrate was found to be 0. 042 N . The amount of acetic acid adsorbed (per gram of charcoal) is: (1) 54 mg (2) 18 mg (3) 36 mg (4) 42 mg JEE Main 2015 (04 Apr) JEE Main Previous Year Paper

Q45.Determination of the molar mass of acetic acid in benzene using freezing point depression is affected by: (1) Complex formation (2) Association (3) Partial ionization (4) Dissociation

Q45.A solution at 20oC is composed of 1.5 mol of benzene and 3.5 mol of toluene. If the vapour pressure of pure benzene and pure toluene at this temperature are 74.7 torr and 22.3 torr respectively, then the total vapour pressure of the solution and the benzene mole fraction in equilibrium with it will be, respectively: (1) 30.5 torr and 0.389 (2) 35.0 torr and 0.480 (3) 38.0 torr and 0.589 (4) 35.8 torr and 0.280

Q46.At 298 K, the standard reduction potentials are 1. 51 V for MnO−4 Mn2+ , 1. 36 V for Cl2|Cl−1., 07 V for Br2|Br−0., 54 V for I2|I− . At pH = 3, permanganate is expected to oxidize: ( RTF = 0.059) (1) Cl− and Br− (2) Br− and I− (3) I− only (4) Cl− , Br− and I−

Q46.A variable, the opposite external potential (Eext) is applied to the cell Zn Zn2+ (1M) ∥Cu2+ (1 M) Cu, of potential 1. 1 V. When Eext < 1.1 V and Eext > 1.1 V, respectively electrons flow from (1) anode to cathode in both the cases. (2) anode to cathode and cathode to anode. (3) cathode to anode and anode to cathode. (4) cathode to anode in both cases.

Q47. A + 2B →C , the rate equation for the reaction is given as Rate = k [A] [B] If the concentration of A is kept the same but that of B is doubled what will happen to the rate itself? (1) Doubled (2) Halved (3) The same (4) Quadrupled