Practice Questions

Q32.While titration dilute HCI solution with aqueous NaOH, which of the following will not be required ? (1) Burette and porcelain tile (2) Pipette and distilled water (3) Clamp and phenolphthalein (4) Bunsen burner and measuring cyclinder

Q32.When gypsum is heated to 393K, it forms: (1) Anhydrous CaSO4 (2) CaSO4 ⋅5H2O (3) CaSO4 ⋅0.5H2O (4) Dead burnt plaster

Q32.The one that is NOT suitable for the removal of permanent hardness of water is : (1) Clark's method (2) Ion–exchange method (3) Calgon's method (4) Treatment with sodium carbonate

Q33.The metal mainly used in devising photoelectric cells is : (1) Na (2) Li (3) Rb (4) Cs

Q33.The condition that indicates a polluted environment is: (1) eutrophication (2) 0. 03% of CO2 in the atmosphere (3) BOD value of 5 ppm (4) pH of rain water to be 5.6

Q33.The incorrect statement(s) among (a) – (d) regarding acid rain is (are): a) It can corrode water pipes (b) It can damage structures made up of stone. (c) It cannot cause respiratory ailments in animals (d) It is not harmful for trees (1) (a), (c) and (d) (2) (c) only (3) (a), (b) and (d) (4) (c) and (d)

Q34.Thermal power plants can lead to : (1) Acid rain (2) Blue baby syndrome (3) Ozone layer depletion (4) Eutrophication

Q34.For the reaction 2A + 3B + 32 C →3P , which statement is correct? (1) dnA dt = 32 dnBdt = 34 dnCdt (2) dnAdt = dnBdt = dnCdt (3) dnA dt = 23 dnBdt = 43 dnCdt (4) dnAdt = 23 dnBdt = 34 dnCdt

Q34.A set of solutions is prepared using 180 g of water as a solvent and 10 g of different non-volatile solutes A, B and C. The relative lowering of vapour pressure in the presence of these solutes are in the order [Given, molar mass of A = 100 g mol−1 ; B = 200 g mol−1 ; C = 10, 000 g mol−1 ] (1) B > C > A (2) C > B > A (3) A > B > C (4) A > C > B

Q35.Among the gases (a) −(e), the gases that cause greenhouse effect are: (a)CO2 (b)H2O (c)CFCs (d)O2 (e)O3 (1) (a), (b), (c) and (d) (2) (a), (b), (c) and (e) (3) (a) and (d) (4) (a), (c), (d) and (e)

Q35.The size of a raw mango shrinks to a much smaller size when kept in a concentrated salt solution. Which one of the following process can explain this? (1) Osmosis (2) Dialysis (3) Diffusion (4) Reverse osmosis

Q35.The processes of calcination and roasting in metallurgical industries, respectively, can lead to : (1) Global warming and photochemical smog (2) Global warming and acid rain (3) Photochemical smog and ozone layer depletion (4) Photochemical smog and global warming Q36. 250 mL of a waste solution obtained from the workshop of a goldsmith contains 0. 1 M AgNO3 and 0. 1M AuCl. The solution was electrolyzed at 2 V by passing a current of 1 A for 15 minutes. The metal/metals electrodeposited will be : (E0Ag+/Ag = 0. 80V, E0Au+/Au = 1. 69V) (1) only gold (2) silver and gold in proportion to their atomic weights (3) only silver (4) silver and gold in equal mass proportion

Q36.The number of sp2 hybrid orbitals in a molecule of benzene is: (1) 24 (2) 6 (3) 18 (4) 12

Q36.For the equilibrium A ⇌B , the variation of the rate of the forward (a) and reverse (b) reaction with time is given by: JEE Main 2020 (04 Sep Shift 1) JEE Main Previous Year Paper (1) (2) (3) (4)

Q36.Identify the correct molecular picture showing what happens at the critical micellar concentration (CMC) of an aqueous solution of a surfactant (1) (D) (2) (B) (3) (A) (4) (C)

Q36.The element that can be refined by distillation is : (1) nickel (2) zinc (3) tin (4) gallium

Q37.The refining method used when the metal and the impurities have low and high melting temperatures, respectively, is (1) liquation. (2) vapour phase refining. (3) zone refining. (4) distillation.

Q37.Match the following: (i) Foam (a) smoke (ii) Gel (b) cell fluid (iii) Aerosol (c) jellies (iv) Emulsion (d) rubber (e) froth (f) milk (1) (i) – (b), (ii) – (c), (iii) – (e), (iv) – (d) (2) (i) – (d), (ii) – (b), (iii) – (a), (iv) – (e) (3) (i) – (e), (ii) – (c), (iii) – (a), (iv) – (f) (4) (i) – (d), (ii) – (b), (iii) – (e), (iv) – (f)

Q37.The reaction of NO with N2O4 at 250 K gives : (1) N2O (2) NO2 (3) N2O3 (4) N2O5

Q37.An Ellingham diagram provides information about: JEE Main 2020 (05 Sep Shift 1) JEE Main Previous Year Paper (1) the conditions of pH and potential under which a species is thermodynamically stable. (2) the temperature dependence of the standard Gibbs energies of formation of some metal oxides. (3) the pressure dependence of the standard electrode potentials of reduction reactions involved in the extraction of metals. (4) the kinetics of the reduction process.

Q37.Kraft temperature is the temperature: (1) below which the aqueous solution of detergents starts freezing. (2) below which the formation of micelles takes place. (3) above which the aqueous solution of detergents starts boiling. (4) above which the formation of micelles takes place.

Q37.Biochemical Oxygen Demand (BOD) is the amount of oxygen required (in ppm ): (1) for sustaining life in a water body. (2) by bacteria to break-down organic waste in a certain volume of a water sample. (3) for the photochemical breakdown of waste present in 1m3 volume of a water body (4) by anaerobic bacteria to breakdown. inorganic waste present in a water body.

Q38.The purest form of commercial iron is: (1) pig iron (2) wrought iron (3) cast iron (4) scrap iron and pig iron

Q38.Amongst the following, the form of water with the lowest ionic conductance at 298K is: (1) distilled water (2) saline water used for intravenous injection (3) water from a well (4) sea water

Q38.Cast iron is used for the manufacture of : (1) wrought iron and pig iron (2) pig iron, scrap iron and steel (3) wrought iron, pig iron and steel (4) wrought iron and steel