Practice Questions

Q38.The incorrect statement(s) among (a) - (c) is (are) : (a) W(VI) is more stable than Cr(VI). (b) in the presence of HCl, permanganate titrations provide satisfactory results. JEE Main 2020 (04 Sep Shift 2) JEE Main Previous Year Paper (c) some lanthanoid oxides can be used as phosphors (1) (b) and (c) only (2) (a) and (b) only (3) (b) only (4) (a) only

Q38.Tyndall effect is observed when : (1) The diameter of dispersed particles is much (2) The diameter of dispersed particles is much larger than the wavelength of light used. smaller than the wavelength of light used (3) The refractive index od dispersed phase is greater (4) The diameter of dispersed particles is similar to than that of the dispersion medium. the wavelength of light used.

Q39.Mischmetal is an alloy consisting mainly of : (1) Lanthanoid metals (2) actinoid and transition metals (3) lanthanoid and actinoid metals (4) actinoid metals

Q39.The presence of soluble fluoride ion upto 1 ppm concentration in drinking water, is : (1) harmful for teeth (2) harmful to skin (3) harmful to bones (4) safe for teeth

Q40.The isomer(s) of [Co(NH3)4Cl2] that has/ have a Cl −Co −Cl angle of 90o, is/are: (1) meridional and trans (2) cis and trans (3) trans only (4) cis only JEE Main 2020 (09 Jan Shift 2) JEE Main Previous Year Paper

Q40.Boron and silicon of very high purity can be obtained through : (1) liquation (2) zone refining (3) vapour phase refining (4) electrolytic refining

Q40.The INCORRECT statement is : (1) bronze is an alloy of copper and tin. (2) cast iron is used to manufacture wrought iron. (3) german silver is an alloy of zinc, copper and (4) brass is an alloy of copper and nickel. nickel.

Q40.Hydrogen has three isotopes (A), (B) and (C). If the number of neutron(s) in (A), (B) and (C) respectively, are (x), (y) and (z), the sum of (x), (y) and (z) is (1) 3 (2) 2 (3) 4 (4) 1

Q40.Which of the following is used for the preparation of colloids ? (1) Ostwald process (2) Van Arkel Method (3) Bredig's Arc Method (4) Mond Process

Q42.The most appropriate reagent for conversion of C2H5 CN into CH3 CH2 CH2 NH2 is : (1) NaBH4 (2) CaH2 (3) LiAlH4 (4) Na(CN) BH3

Q44.If you spill a chemical toilet cleaning liquid on your hand, your first aid would be: (1) vinegar (2) aqueous NaOH (3) aqueous NaHCO3 (4) aqueous NH3

Q44.Two monomers in maltose are: (1) α −D− glucose and β −D− glucose (2) α −D− glucose and α −D− galactose (3) α −D− glucose and α −D− Fructose (4) α −D− glucose and α −D− glucose

Q44.An ionic micelle is formed on the addition of: (1) liquid diethyl ether to aqueous NaCl solution (2) (3) (4) Sodium stearate to pure toluene

Q44.Which one of the following polymers is not obtained by condensation polymerisation ? (1) Nylon 6, 6 (2) Buna – N (3) Bakelite (4) Nylon 6

Q44.If a person is suffering from the deficiency of nor-adrenaline, what kind of drug can be suggested? (1) Anti-inflammatory (2) Antidepressant (3) Antihistamine (4) Analgesic

Q45.Which of the following is not an essential amino acid? (1) Tyrosine (2) Leucine (3) Valine (4) Lysine

Q45.Match the following : (i) Riboflavin (a) Beriberi (ii) Thiamine (b) Scurvy (iii) Pyridoxine (c) Cheilosis (iv) Ascorbic acid (d) Convulsions (1) (i) −(a), (ii) −(d), (iii) −(c), (iv) −(b) (2) (i) −(c), (ii) −(d), (iii) −(a), (iv) −(b) (3) (i) −(c), (ii) −(a), (iii) −(d), (iv) −(b) (4) (i) −(d), (ii) −(b), (iii) −(a), (iv) −(c)

Q45.Match the following drugs with their therapeutic actions: (i) Ranitidine (a) Antidepressant (ii) Nardil (Phenelzine) (b) Antibiotic (iii) Chloramphenicol (c) Antihistamine (iv) Dimetane (Brompheniramine) (d) Antacid (e) Analgesic (1) (i)-(a); (ii)-(c); (iii)-(b); (iv)-(e); (2) (i)-(d); (ii)-(a); (iii)-(b); (iv)-(c); (3) (i)-(e); (ii)-(a); (iii)-(c); (iv)-(d); (4) (i)-(d); (ii)-(c); (iii)-(a); (iv)-(e); Q46. 0. 023 × 1022 molecules are present in 10gof a substance ′x′. The molarity of a solution containing 5g of substance 'x' in 2 L solution is _________ ×10−3

Q46.A 100 mL solution was made by adding 1. 43 g of Na2 CO3. xH2 O. The normality of the solution is 0. 1 N. The value of x is _______ (The atomic mass of Na is 23g/ mol)

Q46.The atomic number of Unnilumium is ______.

Q46.The molarity of HNO3 in a sample which has density 1.4 g/mL and mass percentage of 63% is ________ (Molecular Weight of HNO3 = 63 ) JEE Main 2020 (09 Jan Shift 1) JEE Main Previous Year Paper

Q47.The minimum number of moles of O2 required for complete combustion of 1 mole of propane and 2 moles of butane is..............

Q47.A cylinder containing an ideal gas ( 0.1mol of 1.0dm3 ) is in thermal equilibrium with a large volume of 0.5 molal aqueous solution of ethylene glycol at its freezing point. If the stoppers S1 and S2 (as shown in the figure) are suddenly withdrawn, the volume of the gas in litres after equilibrium is achieved will be _____________. (Given, Kf(water) = 2.0Kkgmol−1, R = 0.08dm3atmK−1mol−1)

Q47.At constant volume, 4 mol of an ideal gas when heated from 300K to 500K changes its internal energy by 5000J. The molar heat capacity at constant volume is ________ JEE Main 2020 (08 Jan Shift 2) JEE Main Previous Year Paper

Q47.The work function of sodium metal is 4. 41 × 10−19J. If photons of wavelength 300 nm are incident on the metal, the kinetics energy of the ejected electrons will be (h = 6. 63 × 10−34J s; c = 3 × 108 m s−1) __________ ×10−21J