Practice Questions

Q31.What quantity (in mL ) of a 45% acid solution of a mono-protic strong acid must be mixed with a 20% solution of the same acid to produce 800 mL of a 29. 875% acid solution? (1) 316 (2) 320 (3) 325 (4) 330

Q32.The most abundant elements by mass in the body of a healthy human adult are: Oxygen (61.4%); Carbon (22.9%), Hydrogen (10.0%); and Nitrogen (2.6%). The weight which a 75kg person JEE Main 2017 (02 Apr) JEE Main Previous Year Paper would gain if all 1𝐻 atoms are replaced by 2𝐻 atoms is: (1) 37.5 kg (2) 7.5 kg (3) 10 kg (4) 15 kg

Q37.At 300 K, the density of a certain gaseous molecule at 2 bar is double to that of dinitrogen (N2) at 4 bar. The molar mass of the gaseous molecule is (1) 224 g mol−1 (2) 112 g mol−1 (3) 56 g mol−1 (4) 28 g mol−1

Q39.A gas undergoes change from state A to state B. In this process, the heat absorbed and work done by the gas is 5 J and 8 J, respectively. Now gas is brought back to A by another process during which 3 J of heat is evolved. In this reverse process of B to A. (1) 6 J of the work will be done by the gas (2) 6 J of the work will be done by the surroundings on gas (3) 10 J of the work will be done by the surroundings (4) 10 J of the work will be done by the gas on gas

Q42.Which one of the following is an oxide? (1) SiO2 (2) KO2 (3) BaO2 (4) CsO2

Q49.What is the standard reduction potential (Eo) for Fe3+ →Fe? Given that: Fe2+ + 2e−→Fe; Eo = −0 .47 V Fe2+ / Fe Fe3+ + e−→Fe2+; Eo = +0 .77 V Fe3+ / Fe2+ (1) −0 .057 V (2) +0 .30 V (3) −0 .30 V (4) +0 .057 V

Q50.The rate of a reaction A doubles on increasing the temperature from 300 to 310 K . By how much, the temperature of reaction B should be increased from 300 K so that rate doubles if activation energy of the reaction B is twice to that of reaction A. (1) 4. 92 K (2) 9. 84 K (3) 19. 67 K (4) 2. 45 K

Q35.If 100 mole of H2O2 decompose at 1 bar and 300 K, the work is done ( kJ) by one mole of O2(g) as it expands against 1 bar pressure is: 2H2O2(l) ⇌2H2O(l) + O2(g) (R = 8 .3 J K−1 mol−1) (1) 124. 50 (2) 249. 00 (3) 498. 00 (4) 62. 25

Q36.A solid XY kept in an evacuated sealed container undergoes decomposition to form a mixture of gases X and Y at temperature T. The equilibrium pressure is 10 bar in this vessel. Kp for this reaction is? (1) 25 (2) 100 (3) 10 (4) 5

Q37.The volume of 0.1 M strong dibasic acid sufficient to neutralize 1g of a base that furnishes 0.04 mole of OH− in aqueous solution is : (1) 400 mL (2) 600 mL (3) 200 mL (4) 800 mL

Q44.An aqueous solution of a salt MX2 at certain temperature has a Van't Hoff factor of 2 . What is the degree of dissociation for this solution of the salt? (1) 0. 50 (2) 0. 33 (3) 0. 67 (4) 0. 80

Q45.Oxidation of succinate ion produces ethylene and carbon dioxide gases. On passing 0. 2 Faraday electricity through an aqueous solution of potassium succinate, what is the total volume of gases (at both cathode and anode) at STP ( 1 atm and 273 K)? (1) 8. 96 L (2) 4. 48 L (3) 6. 72 L (4) 2. 24 L

Q60.Consider the following sequence for aspartic acid: The pH (Isoelectric point) of aspartic acid is: (1) 3.65 (2) 2.77 (3) 5.74 (4) 1.88

Q37.The heat of atomization of methane and ethane are 360 kJ mol−1 and 620 kJ mol−1 , respectively. The longest wavelength of light capable of breaking the C −C bond is (Avogadro's number = 6.023 × 1023, h = 6.62 × 10−34 J s) (1) 2.48 × 104 nm (2) 1.49 × 104 nm (3) 2.48 × 103 nm (4) 1.49 × 103 nm

Q38.Gaseous N2O4 dissociates into gaseous NO2 according to the reaction N2O4(g) ⇌2NO2(g) At 300 K and 1 atm pressure, the degree of dissociation of N2O4 is 0. 2 . If one mole of N2O4 gas is contained in a vessel, then the density of the equilibrium mixture is : (1) 3. 11 g/L (2) 1. 56 g/L (3) 4. 56 g/L (4) 6. 22 g/L

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

Q47.The reaction 2N2O5(g) →4NO2(g) + O2(g) follows first order kinetics. The pressure of a vessel containing only N2O5 was found to increase from 50 mm Hg to 87.5 mm Hg in 30 min. The pressure exerted by the gases after 60 min. Will be (Assume temperature remains constant) : (1) 106.25 mm Hg (2) 125 mm Hg (3) 116.25 mm Hg (4) 150 mm Hg

Q31.The amount of BaSO4 formed upon mixing 100 mL of 20.8%BaCl2 solution with 50 mL of 9.8% H2SO4 solution will be: (Ba = 137, Cl = 35.5, S = 32, H = 1 and O = 16 ) (1) 23.3 g (2) 11.65 g (3) 30.6 g (4) 33.2 g

Q48.How many electrons would be required to deposit 6.35 g of copper at the cathode during the electrolysis of an aqueous solution of copper sulphate? (Atomic mass of copper = 63.5u, NA = Avogadro's constant): (1) NA (2) NA 20 10 (3) NA (4) NA 5 2

Q49.The rate coefficient (k) for a particular reactions is 1.3 × 10−4M−1 s−1 at 100∘C, and 1.3 × 10−3 M−1 s−1 at 150∘C. What is the energy of activation (EA) (in kJ) for this reaction? (R = molar gas constant = 8.314JK−1 mol−1 ) (1) 16 (2) 60 (3) 99 (4) 132

Q35.By how many folds the temperature of a gas would increase when the root mean square velocity of the gas molecules in a container of fixed volume is increased from 5 × 104 cm/s to 10 × 104 cm/s ? (1) Two (2) Three (3) Six (4) Four Q36. 1 1 H2(g) + O2(g) →H2O(l); H2(g) + O2(g) →H2O(g); Given: (I) 2 (II) 2 The molar enthalpy of ΔH∘298 K = −285.9 kJ mol−1 ΔH∘298 K = −241.8 kJ mol−1 vapourisation of water will be : (1) 241.8 kJ mol−1 (2) 22.0 kJ mol−1 (3) 44.1 kJ mol−1 (4) 527.7 kJ mol−1

Q37.In reaction A + 2 B ⇌2C + D, initial concentration of B was 1.5 times of [A], but at equilibrium the concentrations of A and B became equal. The equilibrium constant for the reaction is : (1) 8 (2) 4 (3) 12 (4) 6

Q38.Solid Ba(NO3)2 is gradually dissolved in a 1.0 × 10−4 M Na2CO3 solution. At which concentration of Ba2+ , precipitate of BaCO3 begins to form ? (Ksp for BaCO3 = 5.1 × 10−9) (1) 5.1 × 10−5M (2) 7.1 × 10−8M (3) 4.1 × 10−5M (4) 8.1 × 10−7M

Q39.Given : XNa2HAsO3 + YNaBrO3 + ZHCl →NaBr + H3AsO4 + NaCl The values of X, Y and Z in the above redox reaction are respectively : (1) 2, 1, 2 (2) 2, 1, 3 (3) 3, 1, 6 (4) 3, 1, 4

Q40.Sodium Carbonate cannot be used in place of (NH4)2CO3 for the identification of Ca2+, Ba2+ and Sr2+ ions (in group V ) during mixture analysis because : (1) Mg2+ ions will also be precipitated. (2) Concentration of CO32− ions is very low. (3) Sodium ions will react with acid radicals. (4) Na+ ions will interfere with the detection of Ca2+, Ba2+, Sr2+ ions.