Practice Questions

Q35.An ideal gas is allowed to expand from 1 L to 10 L against a constant external pressure of 1 bar. The work done in kJ is: (1) +10.0 (2) -2.0 (3) -0.9 (4) -9.0

Q35.During compression of a spring the work done is 10 kJ and 2 kJ escaped to the surroundings as heat. The change in internal energy, ΔU(in kJ) is: (1) −8 (2) 8 (3) 12 (4) −12

Q35.The element that shows greater ability to form pπ −pπ multiple bonds is: (1) Sn (2) C (3) Si (4) Ge

Q36.A process will be spontaneous at all temperatures if: (1) ΔH < 0 and ΔS < 0 (2) ΔH < 0 and ΔS > 0 (3) ΔH > 0 and ΔS > 0 (4) ΔH > 0 and ΔS < 0

Q36.Among the following, the set of parameters that represents path functions, is: i) q + w ii) q iii) w iv) H −TS (1) (ii) and (iii) (2) (i), (ii), and (iii) (3) (ii), (iii) and (iv) (4) (i) and (iv)

Q36.The temporary hardness of water is due to: (1) Na2 SO4 (2) NaCl (3) CaCl2 (4) Ca (HCO3)2

Q36.Consider the reversible isothermal expansion of an ideal gas in a closed system at two different temperatures T1 and T2T1 < T2 . The correct graphical depiction of the dependence of work done w vs the final volume V is: (1) (2) (3) (4) Q37.20 ml of 0.1 M H2SO4 solution is added to 30 mL of 0 .2 M NH4OH solution. The pH of the resultant mixture is: pkb of NH4OH = 4 .7 (1) 5.0 (2) 5.2 (3) 9.4 (4) 9.0 JEE Main 2019 (09 Jan Shift 1) JEE Main Previous Year Paper

Q37.Given that, EO2o / H2O = + 1 .23 V; o ES2O82 - / SO42 - = 2 .05 V EBr2o / Br- = + 1 . 09 V; = 1 .4 V EAu3o + / Au The strongest oxidizing agent is (1) O2 (2) S2O82 - (3) Br2 (4) Au3 + Q38.100 mL of a water sample contains 0.81 g of calcium bicarbonate and 0.73 g of magnesium bicarbonate. The hardness of this water sample expressed in terms of equivalents of CaCO3 is: (molar mass of calcium bicarbonate is 162 gm mol-1 and magnesium bicarbonate is 146 g mol-1 ) (1) 100 ppm (2) 1,000 ppm (3) 5,000 ppm (4) 10,000 ppm

Q37.The metal that forms nitride by reacting directly with N2 of air is: (1) Li (2) Rb (3) Cs (4) K

Q37.Given: (i) C(graphite) + O2(g) →CO2(g); ΔrHΘ = x kJ mol−1 (ii) C(graphite) + 12 O2(g) →CO(g) ; ΔrHΘ = y kJ mol−1 (iii) CO(g) + 12 O2(g) →CO2(g); ΔrHΘ = z kJ mol−1 Based on the above thermochemical equations, find out which one of the following algebraic relationships is correct? (1) x = y + z (2) z = x + y (3) y = 2z −x (4) x = y −z

Q37.Magnesium powder burns in air to give (1) MgO and Mg3N2 . (2) MgO only. (3) Mg(NO3)2 and Mg3N2 . (4) MgO and Mg(NO3)2 . JEE Main 2019 (09 Apr Shift 1) JEE Main Previous Year Paper

Q37.The amphoteric hydroxide is: (1) Be(OH)2 (2) Ca(OH)2 (3) Mg(OH)2 (4) Sr(OH)

Q38.The correct statements among I to III regrading group 13 element oxides are, (I) Boron trioxide is acidic. (II) Oxides of aluminum and gallium are amphoteric. (III) Oxides of indium and thallium are basic. (1) (I) and (III) only (2) (I) and (II) only (3) (I), (II) and (III) (4) (II) and (III) only

Q38.The total number of isotopes of hydrogen and number of radioactive isotopes among them, respectively, are (1) 2 and 1 (2) 2 and 0 (3) 3 and 1 (4) 3 and 2

Q38.The synonym for water gas when used in the production of methanol is: (1) syn gas (2) laughing gas (3) natural gas (4) fuel gas

Q38. C60, an allotrope of carbon contains (1) 12 hexagons and 20 pentagons. (2) 16 hexagons and 16 pentagons. (3) 18 hexagons and 14 pentagons. (4) 20 hexagons and 12 pentagons.

Q38.What is the IUPAC name of the following compound? (1) 4−Bromo −3−methylpent −2−ene (2) 3−Bromo −3−methyl −1, 2−dimethylprop −1− ene (3) 2−Bromo −3−methyl pent −3−ene (4) 3−Bromo −1, 2−dimethylbut −1−ene

Q39.Given: Co3 + + e- →Co2 + ; E° = + 1.81V Pb3 + + 2e- →Pb2 + ; E° = + 1.67V Ce4 + + e- →Ce3 + ; E° = + 1.61V Bi3 + + 3e- →Bi; E° = + 0.20V Oxidizing power of the species will increase in the order: (1) Co3 + < Ce4 + < Bi3 + < Pb4 + (2) Bi3 + < Ce4 + < Pb4 + < Co3 + (3) Co3 + < Pb4 + < Ce3 + < Bi4 + (4) Ce4 + < Pb4 + < Bi3 + < Co3 +

Q39.The relative stability of +1 oxidation state of group 13 elements follows the order (1) Al < Ga < Tl < In (2) T1 < In < Ga < Al (3) Ga < Al < ln < Tl (4) Al < Ga < In < Tl

Q39.NaH is an example of: (1) Electron −richhydride (2) Metallichydride (3) Salinehydride (4) Molecularhydride

Q39.The metal used for making X-ray tube window is: (1) Mg (2) Na (3) Be (4) Ca

Q39.The alloy used in the construction of aircrafts is: (1) Mg −Al (2) Mg −Mn (3) Mg −Sn (4) Mg −Zn

Q39.The pH of rain water is approximately: (1) 5.6 (2) 6.5 (3) 7.5 (4) 7.0

Q39.The amorphous form of silica is: (1) quartz (2) kieselguhr (3) tridymite (4) cristobalite

Q39.The covalent alkaline earth metal halide X = Cl, Br, I is: (1) CaX2 (2) MgX2 (3) SrX2 (4) BeX2